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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549





Form 10-K







|☒ | ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
|- | ------------------------------------------------------------------------------------

For the fiscal year ended June 30, 2018

OR



|☐ | TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
|- | ----------------------------------------------------------------------------------------

For the transition period from
 to
 .

Commission File No. 000-08565





Marine Petroleum Trust

(Exact name of registrant as specified in its charter)







|                                         |  |                    
|---------------------------------------- |  | -------------------
|Texas                                    |  | 75-6008017         
|(State or other jurisdiction of          |  | (I.R.S. Employer   
|incorporation or organization)           |  | Identification No.)
|                                         | 
|c/o Corporate Trustee:                   |  |                    
|Simmons Bank                             |  |                    
|2911 Turtle Creek Blvd., Suite 850,      |  |                    
|Dallas, Texas                            |  | 75219              
|(Address of principal executive offices) |  | (Zip Code)         

Registrants telephone number, including area code

(at the office of the Corporate Trustee):

(855) 588-7839

Securities registered pursuant to Section 12(b) of the Act:

None

Securities
registered pursuant to Section 12(g) of the Act:

Units of Beneficial Interest

(Title of Class)





Indicate by
check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    YES  ☐    NO  ☒

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the
Act.    YES  ☐    NO  ☒

Indicate by check mark whether the
registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and
(2) has been subject to such filing requirements for the past 90 days.    YES  ☒    NO  ☐

Indicate by check mark whether the registrant has submitted electronically, every Interactive Data File required to be submitted pursuant to
Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such
files).    YES  ☐    NO  ☐

Indicate by check mark if disclosure of
delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrants knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.  ☒

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a
non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of large accelerated filer, accelerated filer, smaller reporting
company, and emerging growth company in Rule 12b-2 of the Exchange Act. (Check one):



|                        |  |   |  |                           |  |  
|----------------------- |  | - |  | ------------------------- |  | -
|Large accelerated filer |  | ☐ |  | Accelerated filer         |  | ☐
|                        |  |   | 
|Non-accelerated filer   |  | ☐ |  | Smaller reporting company |  | ☒
|                        |  |   | 
|                        |  |   |  | Emerging Growth Company   |  | ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended
transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the
Act).    YES  ☐    NO  ☒

The aggregate market value of units of
beneficial interest held by non-affiliates of the registrant at December 29, 2017 (the last business day of the registrants most recently completed second fiscal quarter) was approximately
$6.1 million. (For purposes of determination of the above stated amount, only directors, executive officers and 10% or greater unitholders have been deemed affiliates.)

The number of units of beneficial interest outstanding as of September 1, 2018 was 2,000,000









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TABLE OF CONTENTS



|         |  |                                                                                                              |  |      |    | 
|-------- |  | ------------------------------------------------------------------------------------------------------------ |  | ---- | -- | 
|         |  |                                                                                                              |  | Page |   
|         |  |                                                                                                             
|PART I   |  |                                                                                                              |  |      |    | 
|         |  |                                                                                                             
|Item 1.  |  | Business                                                                                                     |  |      | 3  | 
|         |  |                                                                                                             
|Item 1A. |  | Risk Factors                                                                                                 |  |      | 5  | 
|         |  |                                                                                                             
|Item 1B. |  | Unresolved Staff Comments                                                                                    |  |      | 9  | 
|         |  |                                                                                                             
|Item 2.  |  | Properties                                                                                                   |  |      | 9  | 
|         |  |                                                                                                             
|Item 3.  |  | Legal Proceedings                                                                                            |  |      | 12 | 
|         |  |                                                                                                             
|Item 4.  |  | Mine Safety Disclosures                                                                                      |  |      | 12 | 
|         |  |                                                                                                             
|PART II  |  |                                                                                                              |  |      |    | 
|         |  |                                                                                                             
|Item 5.  |  | Market for Registrants Common Equity, Related Unitholder Matters and Issuer
 Purchases of Equity Securities |  |      | 13 | 
|         |  |                                                                                                             
|Item 6.  |  | Selected Financial Data                                                                                      |  |      | 13 | 
|         |  |                                                                                                             
|Item 7.  |  | Trustees Discussion and Analysis of Financial Condition and Results of Operations                           |  |      | 15 | 
|         |  |                                                                                                             
|Item 7A. |  | Quantitative and Qualitative Disclosures About Market Risk                                                   |  |      | 18 | 
|         |  |                                                                                                             
|Item 8.  |  | Financial Statements and Supplementary Data                                                                  |  |      | 18 | 
|         |  |                                                                                                             
|Item 9.  |  | Changes in and Disagreements with Accountants on Accounting and Financial Disclosure                         |  |      | 19 | 
|         |  |                                                                                                             
|Item 9A. |  | Controls and Procedures                                                                                      |  |      | 19 | 
|         |  |                                                                                                             
|Item 9B. |  | Other Information                                                                                            |  |      | 19 | 
|         |  |                                                                                                             
|PART III |  |                                                                                                              |  |      |    | 
|         |  |                                                                                                             
|Item 10. |  | Directors, Executive Officers and Corporate Governance                                                       |  |      | 20 | 
|         |  |                                                                                                             
|Item 11. |  | Executive Compensation                                                                                       |  |      | 20 | 
|         |  |                                                                                                             
|Item 12. |  | Security Ownership of Certain Beneficial Owners and Management and Related Unitholder
 Matters               |  |      | 20 | 
|         |  |                                                                                                             
|Item 13. |  | Certain Relationships and Related Transactions, and Director Independence                                    |  |      | 21 | 
|         |  |                                                                                                             
|Item 14. |  | Principal Accounting Fees and Services                                                                       |  |      | 21 | 
|         |  |                                                                                                             
|PART IV  |  |                                                                                                              |  |      |    | 
|         |  |                                                                                                             
|Item 15. |  | Exhibits, Financial Statement Schedules                                                                      |  |      | 22 | 



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PART I



|ITEM 1. | BUSINESS
|------- | --------

Organization. Marine Petroleum Trust (the Trust) is a royalty trust that was created in 1956 under the laws of the State of
Texas. Effective February 20, 2018, Simmons Bank became corporate trustee of the Trust (the Trustee) as a result of a merger between Simmons Bank and Southwest Bank, the former corporate Trustee of the Trust. The Trusts
Indenture (the Indenture) provides that the term of the Trust will expire on June 1, 2021, unless extended by the vote of the holders of a majority of the outstanding units of beneficial interest. The Trust is not permitted to
engage in any business activity because it was organized for the sole purpose of providing an efficient, orderly and practical means for the administration and liquidation of rights to payments from certain oil and natural gas leases in the Gulf of
Mexico, pursuant to license agreements and amendments between the Trusts predecessors and Gulf Oil Corporation (Gulf). As a result of various transactions that have occurred since 1956, these interests are now held by Chevron
Corporation (Chevron) and its assignees, including Arena Energy, LP (Arena, and collectively with Chevron and its assignees, the Interest Owners).

The indenture pursuant to which the Trust was created (as amended, the Indenture) provides that the corporate trustee is to
distribute all cash in the Trust, less an amount reserved for the payment of accrued liabilities and estimated future expenses, to unitholders of record on the last business day of February, May, August and November. Payments are to be made on the
28th day of September, December, March and June of each fiscal year. If the 28th falls on a Saturday, Sunday or legal holiday, the distribution
is payable on the next succeeding business day.

The Indenture prohibits the operation of any kind of trade or business by the Trust and
also provides that the term of the Trust will expire on June 1, 2021, unless extended by the vote of the holders of a majority of the outstanding units of beneficial interest.

Effective October 19, 2017, Simmons First National Corporation (SFNC) completed its acquisition of First Texas BHC, Inc., the
parent company of Southwest Bank. SFNC is the parent of Simmons Bank. SFNC merged Southwest Bank, the former corporate Trustee of the Trust, with Simmons Bank effective February 20, 2018. The defined term Trustee as used herein
shall refer to Southwest Bank for periods from May 30, 2014 through February 19, 2018 and to Simmons Bank for periods on and after February 20, 2018.

The Trusts wholly owned subsidiary, Marine Petroleum Corporation (MPC, and collectively with the Trust, Marine),
holds title to interests in properties that are situated offshore of Louisiana, because at the time the Trust was created, trusts could not hold these interests under Louisiana law. Ninety-eight percent of all oil, natural gas, and other mineral
royalties collected by MPC, less the receiving and collection costs, are retained by and delivered to the Trust. MPC retains the remaining two percent of the overriding royalties along with other items of income and expense until the board of
directors declares a dividend out of the corpus. MPC, like the Trust, is prohibited from engaging in a trade or business and only takes those actions that are necessary for the administration and liquidation of its properties. Marines only
industry segment or purpose is the administration and collection of royalties.

Royalties. Marines rights are generally
referred to as overriding royalty interests in the oil and natural gas industry, and are sometimes referred to as overriding royalty interests in this Annual Report on Form 10-K. An overriding royalty interest
is created by an assignment by the owner of a working interest in an oil or natural gas lease. All production and marketing functions are conducted by the working interest owners of the leases. Income from overriding royalties is paid to Marine
either (i) on the basis of the selling price of oil, natural gas and other minerals produced, saved or sold, or (ii) at the value at the wellhead as determined by industry standards, when the selling price does not reflect the value at the
wellhead.

Marine holds an overriding royalty interest equal to three-fourths of 1% of the value at the well of any oil, natural gas, or
other minerals produced and sold from the leases described in the Properties section below. Marines overriding royalty interest applies only to existing leases and does not apply to new leases that the Interest Owners may acquire.



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Marine also owns a 32.6% interest in Tidelands Royalty Trust B
(Tidelands), a separate Texas trust, which owns interests in four leases covering an aggregate of 17,188 gross acres. The term of the Tidelands royalty trust will expire in 2021, unless extended by the affirmative vote of the holders of
a majority of the outstanding units of beneficial interest. Tidelands indenture provides that the Trustee is to distribute all cash in the trust, less an amount reserved for payment of accrued liabilities and estimated future expenses, to
unitholders of record on the last business day of March, June, September and December of each year. Pursuant to the Indenture, such distributions are to be made within 15 days of the record date. Distributable income is paid from the unconsolidated
account balances of Tidelands. Distributable income is comprised of (i) royalties from offshore Texas leases owned directly by Tidelands, plus (ii) 95% of the overriding royalties received by its subsidiary that are retained by and delivered to
Tidelands on a quarterly basis, less (iii) administrative expenses of Tidelands. Marine recommends that you read Tidelands public filings for a description of its risks, business, properties and financial condition and results of
operations.

As of the date of filing of this Annual Report on Form 10-K, the leases subject to
Marines interests cover an aggregate of 217,056 gross acres (including Tidelands interest in 17,188 gross acres). These leases will remain in force until the leases terminate or expire pursuant to their respective terms. Leases may be
voluntarily released by the working interest owner after oil and natural gas reserves are produced. Leases may also be abandoned by the working interest owner due to the failure to discover and produce sufficient reserves to make development
economically worthwhile. In addition, the U.S. federal government may terminate a lease if the working interest owner fails to develop a lease once it is acquired.

For the fiscal year ended June 30, 2018, approximately 93% of Marines royalty revenues were attributable to the sale of oil and
approximately 7% of Marines royalty revenues were attributable to the sale of natural gas. The royalty revenues received by Marine are affected by a number of factors, including seasonal fluctuations in demand, the ability of wells to produce
due to depletion and changes in the market prices for oil and natural gas. The following table presents the percent of royalties received from various working interest owners, which account for the royalties received in each of the past three years.



|                                   |  |                           |     |   |      |  |     |      |  |  |     |  
|---------------------------------- |  | ------------------------- | --- | - | ---- |  | --- | ---- |  |  | --- | -
|                                   |  | Fiscal Year EndedJune 30, |    
|Company                            |  | 2018                      |     |   | 2017 |  |     | 2016 | 
|Arena Energy, LP                   |  |                           | 90  | % |      |  | 63  | %    |  |  | 21  | %
|Chevron USA, Inc.                  |  |                           | 6   | % |      |  | 26  | %    |  |  | 59  | %
|Fieldwood Energy LLC               |  |                           | 4   | % |      |  | 9   | %    |  |  | 8   | %
|Walter Energy, Inc.                |  |                           |    |   |      |  | 1   | %    |  |  | 5   | %
|Anglo Suisse Offshore Partners LLP |  |                           |    |   |      |  |    |      |  |  | 3   | %
|Century Energy Ltd.                |  |                           |    |   |      |  |    |      |  |  | 3   | %
|Others                             |  |                           |    |   |      |  | 1   | %    |  |  | 1   | %
|                                   |  |                           |     |   |      |  |     |      |  |  |     |  
|                                   |  |                           | 100 | % |      |  | 100 | %    |  |  | 100 | %

In addition, Marines revenues from its interest in Tidelands accounted for approximately 0.01%, 3% and
8% of Marines revenues for the fiscal years ended June 30, 2018, 2017 and 2016, respectively. Tidelands has reported that royalty revenues from Renaissance Offshore LLC and Fieldwood Energy LLC accounted for more than 90% of
Tidelands royalty revenue for each of the years ended December 31, 2017, 2016 and 2015.

Marine derives no revenues from
foreign sources and has no export sales.

Trust Functions. The Trust is administered by officers and employees of its Trustee. The
Trust has no employees. See Item 10. Directors, Executive Officers and Corporate Governance.

All aspects of
Marines operations are conducted by third parties. These operations include the production and sale of oil and natural gas and the calculation of royalty payments to Marine, which are conducted by oil and natural gas companies that lease
tracts subject to Marines interests. American Stock Transfer and Trust Company, LLC is the transfer agent for Marine and is responsible for reviewing, processing and paying distributions.



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The ability of Marine to receive revenues is entirely dependent upon its rights with respect to
the leases held by the Interest Owners in the Gulf of Mexico (as more fully described in Item 2. Propertiesbelow). Moreover, no revenues are payable to Marine until sales of production commence from any such lease.

The royalty interests held by Marine are depleting with each barrel of oil and cubic foot of natural gas produced. No funds are reinvested by
Marine; thus, these depleting assets are not being replaced.

Widely Held Fixed Investment TrustReporting
Information.The Trustee assumes that some units of beneficial interest are held by middlemen, as such term is broadly defined in U.S. Treasury Regulations (and includes custodians, nominees, certain joint owners and brokers holding an
interest for a customer in street name). Therefore, the Trustee considers the Trust to be a widely held fixed investment trust (WHFIT) for U.S. federal income tax purposes. Accordingly, the Trust will provide tax information in
accordance with applicable U.S. Treasury Regulations governing the information reporting requirements of the Trust as a WHFIT. The Trustee that will provide the required information and the contact information for the Trustee is as follows:

Simmons Bank

2911 Turtle Creek
Blvd., Suite 850

Dallas, Texas 75219

Telephone number: (855) 588-7839

Each unitholder should consult its own tax advisor for compliance with U.S. federal income tax laws and regulations.



|ITEM 1A. | RISK FACTORS
|-------- | ------------

Although various risk factors and specific cautionary statements are described elsewhere in this Annual Report on Form 10-K, the following is a summary of the principal risks associated with the Trust and an investment in units of the Trust.

Oil and natural gas prices, which are subject to fluctuations, have declined substantially from historical highs and may remain depressed for the
foreseeable future. The depression in oil and natural gas prices has resulted in, and is expected to continue to result in, lower royalty payments to Marine and lower cash distributions to its unitholders.

Marines quarterly distributions are highly dependent upon the prices realized from the sale of oil and natural gas. Any sustained
decline in Marines distributable income would cause a decrease in the value of cash distributions to its unitholders and could result in Marine being unable to make a cash distribution to its unitholders in one or more quarters, as well as
result in a decrease of the market price of the units.

Historically, oil and natural gas prices have been volatile and are likely to
continue to be volatile in the future due to factors beyond Marines control. These factors include, but are not limited to:



| |  |  | political conditions worldwide, and in particular, political disruptions, terrorist activities, wars or other
armed conflicts in oil producing regions;
| | - |  | -------------------------------------------------------------------------------------------------------------------------------------------------------



| |  |  | worldwide economic conditions;
| | - |  | ------------------------------



| |  |  | weather conditions;
| | - |  | -------------------



| |  |  | technological innovation affecting extraction expenses;
| | - |  | -------------------------------------------------------



| |  |  | the supply and price of domestic and foreign oil and natural gas;
| | - |  | -----------------------------------------------------------------



| |  |  | the level of consumer demand;
| | - |  | -----------------------------



| |  |  | the price and availability of alternative fuels;
| | - |  | ------------------------------------------------



| |  |  | the proximity to, and capacity of, transportation facilities; and
| | - |  | -----------------------------------------------------------------



| |  |  | the effect of worldwide energy conservation measures.
| | - |  | -----------------------------------------------------

Moreover, government regulations, such as the regulation of natural gas transportation and price controls, can affect oil and natural gas
prices in the long term.



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Lower prices may reduce the amount of oil and natural gas that is economical to produce and
reduce distributable income available to Marine. As a result, a substantial decline in the production or price of oil and natural gas could result in Marine being unable to make distributions to unitholders in future quarters. The volatility of oil
and gas prices reduces the predictability of future cash distributions to unitholders. Substantially all of the oil and natural gas produced from the leases are being sold under short-term or multi-month contracts at market clearing prices or on the
spot market.

Marine is unable to acquire royalty interests in any more leases.

Marines overriding royalty interests apply only to existing leases and do not apply to new leases that the Interest Owners may acquire.
Therefore, the Interest Owners are no longer obligated to assign any interest to Marine out of any lease that they acquire. In addition, Marine is not permitted to carry on any business, including making investments in additional oil and natural gas
interests. Marine will continue to be entitled to receive payments on its existing leases, so long as the leases are active properties. Once the leases terminate or expire, any overriding royalties payable to Marine will terminate and Marine will
not be able to acquire any additional or replacement royalty interests.

Royalty interests are depleting assets and may deplete faster than expected or
in their entirety.

The net proceeds payable to Marine are derived from the sale of depleting assets. Accordingly, the portion of the
distributions to unitholders that are attributable to depletion may be considered a return of capital as opposed to a return on investment. Distributions that are considered a return of capital will ultimately diminish the depletion tax benefits
available to unitholders, which could reduce the market value of the units over time.

The reduction in proved reserve quantities is a
common measure of depletion. Future maintenance and development projects on the leases will likely affect the quantity of proved reserves. The timing and size of these projects will depend on the market prices of oil and natural gas. If operators of
the leases do not implement additional maintenance and development projects, the future rate of production decline of proved reserves may be higher than the rate currently experienced by Marine. Eventually, the properties in the leases will stop
producing in commercial quantities, and Marine will cease to be entitled to receive any distributions of net proceeds therefrom.

The market price for
the units may not reflect the value of the royalty interests held by Marine.

The public trading price for the units tends to be tied
to the recent and expected levels of cash distributions on the units. The amounts available for distribution by Marine vary in response to numerous factors outside of Marines control, including prevailing prices for oil and natural gas
produced from properties on the leases. The market price of the units is not necessarily indicative of the value that Marine would realize if it sold its interest in the properties on the leases to a third party buyer and distributed the net
proceeds to its unitholders. In addition, the market price of the units is not necessarily reflective of the fact that Marines assets are depleting assets, and a portion of each cash distribution paid on the units should be considered by
investors as a return of capital, with the remainder being considered as a return on investment. There is no guarantee that distributions made to a unitholder over the life of these depleting assets will equal or exceed the purchase price paid by
the unitholder for the unit.

In addition, the public stock markets have traditionally experienced price and trading volume volatility.
This volatility has had a significant effect on the market prices of securities issued by many companies for reasons that may or may not be related to operating performance. If the public stock markets continue to experience price and trading volume
volatility in the future, the market price of the units could be adversely affected.

Our units have been thinly traded and an active trading market
for our units may not develop.

The trading volume of our units has historically been low. As a result, sales of small amounts of the
units in the public market could cause the price of the units to fluctuate greatly, including in a materially adverse manner. In addition, a more active trading market for our units may not develop, or if it does develop, may not continue, and a
unitholder may find it difficult to dispose of, or to obtain accurate quotations as to the market value of, our units.



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Operating risks for the working interest owners interests on the leases can adversely affect
distributions.

The occurrence of drilling, production or transportation accidents and other natural disasters on the properties
underlying the leases can reduce distributions. These occurrences include blowouts, cratering, explosions, environmental and hurricane damage that may result in personal injuries, property damage, damage to productive formations or equipment and
environmental damages. Any of these occurrences could have a material adverse effect on the amount of our distributions or the market value of the units.

Failure to collect royalty payments from working interest owners could adversely affect Marines distributions to its unitholders.

A significant portion of Marines royalties are attributable to a limited number of working interest owners. For the fiscal year ended
June 30, 2018, three working interest owners accounted for approximately 100% of the royalty payments to Marine. Marine does not require working interest owners to pledge collateral or otherwise post security for royalty payments. At any time,
Marine may encounter collection issues with one or more of the working interest owners, which could result in Marine not receiving payments for some or all of its royalty interests. Any reduction in royalty payments would reduce the distributable
income to Marines unitholders.

The owner of any properties in the leases may transfer any of the properties to another unrelated third party,
which could reduce the amount of royalty payments that are received.

The working interest owners may at any time transfer all or part
of the property in a lease to another unrelated third party. Unitholders are not entitled to vote on any transfer, and Marine will not receive any proceeds of any such transfer. Following any transfer, the lease will continue to be subject to
Marines royalty interest, but the net proceeds from the transferred property would be calculated separately and paid by the transferee. The transferee would be responsible for all of the obligations relating to calculating, reporting and
paying to Marine its royalty interest on the transferred portion of the lease, and the transferor of the transferred property would have no continuing obligation to Marine for that property. Any such transferee may not be as financially sound as the
current working interest owner.

The owner of any properties in the leases may abandon any property, terminating the related royalty interest Marine
may hold.

The current working interest owners or any transferee may abandon any well or property that is subject to Marines
royalty interest if it believes that the well or property can no longer produce in commercially economic quantities or for any other reason. This would terminate Marines royalty interest relating to the abandoned well or property.

The Trustee, Marine and the Trusts unitholders do not control the operation or development of the properties in the leases and have little influence
over their operation or development.

The Trustee, Marine and the Trusts unitholdershave little, if any, influence or
control over the operation or future development of the underlying properties of the leases. The properties underlying the leases are owned by independent working interest owners. The working interest owners manage the underlying properties and
handle the receipt and payment of funds relating to the leases and payments to Marine for its royalty interests. The current working interest owners are under no obligation to continue operating the properties. The failure of a working interest
owner to conduct its operations, discharge its obligations, cooperate with regulatory agencies or comply with laws, rules and regulations in a proper manner could have an adverse effect on net proceeds payable to Marine. The Trustee, Marine and the
Trusts unitholdersdo nothave the right to replace an operator.

Important reserve and other information with respect to the
particular leases subject to Marines royalty interest is unreasonably difficult to obtain.

The leasehold working interests that
are subject to the rights held by Marine are owned, in most cases, in whole or in part by Arena, or other oil and natural gas exploration and production companies. Certain



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information with respect to the particular leases subject to Marines interests, including, but not limited to, (i) reserves, (ii) the availability of oil and natural gas,
(iii) the average production cost (lifting cost) per unit, (iv) undeveloped acreage and (v) net wells and net acres, lies solely within the knowledge of these working interest owners. Marine does not have access to engineering data
regarding these leaseholds and believes that such information would have been compiled principally by or for the working interest owners of these leaseholds and such information is unreasonably difficult for Marine to obtain.

Terrorism and continued geopolitical hostilities could adversely affect Marines distributions to its unitholders or the market price of its units.

Terrorist attacks and the threat of terrorist attacks, whether domestic or foreign, as well as military or other actions taken in
response to such attacks or threats, could cause instability in the global financial, oil and natural gas markets. Terrorism and other geopolitical hostilities could adversely affect the Trusts distributions to its unitholders or the market
price of its units in unpredictable ways, including through the disruption of oil and natural gas supplies and markets, increased volatility in oil and natural gas prices, or the possibility that the infrastructure on which the operators of the
underlying properties rely could be a direct target or an indirect casualty of an act of terror.

Unitholders have limited voting rights.

Voting rights as a unitholder are more limited than those of stockholders of most public corporations. For example, there is no requirement for
annual meetings of unitholders or for an annual or other periodic re-election of the Trustee. Unlike corporations, which are generally governed by boards of directors that are elected by their equity holders,
the Trust is administered by a corporate trustee in accordance with the Indenture and other organizational documents. The Trustee has extremely limited discretion in its administration of the Trust.

The limited liability of the unitholders is uncertain.

The unitholders are not protected from the liabilities of the Trust to the same extent that a shareholder would be protected from a
corporations liabilities. The structure of the Trust as a trust does not include the interposition of a limited liability entity, such as a corporation or limited partnership, which would provide further limited liability protection to
unitholders. While the Trust is liable for any excess liabilities incurred if the Trustee fails to ensure that such liabilities are to be satisfied only out of the Trusts assets, under the laws of the State of Texas, which are unsettled on
this point, a unitholder may be jointly and severally liable for any liability of the Trust if (i) the satisfaction of such liabilities was not contractually limited to the assets of the Trust and (ii) the assets of the Trust and the
Trustee are not adequate to satisfy such liability. As a result, unitholders may be exposed to personal liability.

Marines royalty interest can
be sold and the Trust can be terminated.

The Trust may be terminated and the Trustee may sell Marines royalty interests if
holders of 80% or more of the units of beneficial interest of the Trust approve the sale and vote to terminate the Trust. Following any such termination and liquidation, the net proceeds of any sale would be distributed to the unitholders and the
unitholders would receive no further distributions from the Trust. Any such sale may not be on terms acceptable or favorable to all unitholders.

The
operators of the oil and natural gas leases are subject to extensive governmental regulation.

Oil and natural gas operators have been,
and in the future will be, affected by Federal, state and local laws and regulations and other political developments, such as price or gathering rate controls, drilling regulations, and environmental protection regulations, including the regulation
of hydraulic fracturing. Although Marine is unable to predict changes to existing laws and regulations, such changes could significantly impact Marines overriding royalty interests.



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Cash held by the Trustee is not insured by the Federal Deposit Insurance Corporation.

Currently, cash held by Marine that is reserved for the payment of accrued liabilities and estimated future expenses and distributions to
unitholders is typically held in cash deposits, U.S. Treasury and agency bonds and money market accounts. Marine places such reserve cash with financial institutions that Marine considers credit worthy and limits the amount of credit exposure from
any one financial institution. However, none of these accounts are insured by the Federal Deposit Insurance Corporation. In the event that any such financial institution becomes insolvent, Marine may be unable to recover any or all such cash from
the insolvent financial institution. Any loss of such cash may have a material adverse effect on Marines cash balances and any distributions to unitholders.

Financial information of Marine is not prepared in accordance with generally accepted accounting principles in the United States.

The financial statements of Marine are prepared on a modified cash basis of accounting, which is a comprehensive basis of accounting that
differs from generally accepted accounting principles in the United States (GAAP). Although the modified cash basis of accounting is permitted for royalty trusts by the U.S. Securities and Exchange Commission (the SEC), the
financial statements of Marine differ from financial statements prepared in accordance with GAAP because royalty income is recognized in the month it is received rather than in the month of production, expenses are recorded in the month paid rather
than in the month incurred and reserves may be established for contingencies that would not be recorded under GAAP.

If Marine becomes subject to the
Texas franchise tax, the Trustee may have to withhold amounts from future distributions to pay the tax liability.

The State of Texas
imposes a franchise tax that applies to most business entities doing business in Texas. Trusts, however, other than business trusts (as defined in U.S. Treasury Regulation section 301.7701-4(b)), that meet
certain statutory requirements are exempt from the franchise tax as passive entities.

The Trustee does not expect that the
Trust will be required to pay any amounts under the Texas franchise tax for the 2018 tax year based on the Trustees belief that the Trust is exempt from the franchise tax as a passive entity (i.e., the Trust is not a business trust, it
receives at least 90% of its federal gross income from certain passive sources, and no more than 10% of its income is derived from an active trade or business). If it is subsequently determined that the Trust is not exempt from the franchise tax,
the Trust will be required to reduce distributions by the amount required to satisfy and pay the Trusts franchise tax liability for the years for which the applicable statute of limitations has not yet expired. In addition, the Trust would be
required to timely pay franchise tax liability due with respect to current and future years in which the Trust fails to qualify for an exemption and has total revenues in excess of $1 million (subject to adjustment pursuant to Texas Tax Code
section 171.006).

If the Trust is exempt from the Texas franchise tax as a passive entity, each unitholder that is subject to the Texas
franchise tax as a taxable entity under the Texas Tax Code should generally include its share of the Trusts revenue in its franchise tax computation. The Texas franchise tax does not apply to natural persons. Each unitholder is urged to
consult its own tax advisor regarding its possible Texas franchise tax liability.



|ITEM 1B. | UNRESOLVED STAFF COMMENTS
|-------- | -------------------------

Not applicable.



|ITEM 2. | PROPERTIES
|------- | ----------

General. Marine is not engaged in oil and natural gas exploration or production operations, and its only industry segment or purpose is
the administration and collection of royalties. Marines income is based upon the oil and natural gas operations of third parties. Marines income is derived from contracts that provide for payments in the nature of overriding royalties
made to Marine based on oil and natural gas sales from certain leases in the Gulf of Mexico. Marine does not own or directly lease any physical properties.



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##### Table of Contents

Reserves. As indicated above, Marine is not engaged in the exploration or production of
oil or natural gas. Marines income is derived from overriding royalty payments that are carved out of working interests in oil and natural gas leases in the Gulf of Mexico. Marine does not have the engineering data necessary to make an
estimate of the proved oil and natural gas reserves attributable to such working interests (nor the present value of future net cash flows from such reserves), and Marine is not entitled to receive such data from the owners of the working interests
from which its interests are derived. Similarly, Tidelands does not have access to the engineering data necessary to make an estimate of the proved oil and natural gas reserves attributable to such working interests. See also
Difficulty in Obtaining Certain Data. Since Marine does not have access to this reserve information, Marine is unable to compute the standardized measure of discounted future net cash flows attributable to such working
interests.

Marine did not file any reports during the fiscal year ended June 30, 2018 with any U.S. Federal authority or agency with
respect to oil and natural gas reserves.

Due to the nature of Marines business, it does not have any delivery commitments.

Production. Information regarding the net quantities of oil and natural gas sold with respect to Marines overriding royalty
interests (excluding its interest in Tidelands) for each of the last three fiscal years, as well as the average sales price per unit of oil and natural gas sold upon which payments to Marine are based, is set forth in the following table:



|                                                          |  |                            |        |  |      |   |        |      |  |   |        | 
|--------------------------------------------------------- |  | -------------------------- | ------ |  | ---- | - | ------ | ---- |  | - | ------ | 
|                                                          |  | Fiscal Year Ended June 30, |       
|                                                          |  | 2018                       |        |  | 2017 |   |        | 2016 | 
|Net quantities sold:                                      |  |                            |        |  |      |   |        |      |  |   |        | 
|Oil (in barrels (bbls))                                 |  |                            | 15,138 |  |      |   | 18,439 |      |  |   | 15,841 | 
|Natural gas (in thousands of cubic feet (mcf))          |  |                            | 20,664 |  |      |   | 40,867 |      |  |   | 56,719 | 
|Average sales price for royalty oil and natural gas sold: |  |                            |        |  |      |   |        |      |  |   |        | 
|Oil (per bbl) (1)                                         |  | $                          | 50.76  |  |      | $ | 45.06  |      |  | $ | 44.80  | 
|Natural gas, net of expenses (per mcf) (1)                |  | $                          | 3.10   |  |      | $ | 2.19   |      |  | $ | 2.11   | 



|(1) | The average sales price is calculated from data provided by the operators.
|--- | --------------------------------------------------------------------------

Information about average production cost (lifting cost) per unit of production has been omitted due to its unavailability and inapplicability
to Marine. For more recent information regarding prices, see Item 7. Trustees Discussion and Analysis of Financial Condition and Results of Operations.

Productive Wells. Based on the latest public records reviewed by Marine from the Bureau of Ocean Energy Management, Regulation and
Enforcement, a division of the U.S. government, there were approximately 201 gross active wells subject to Marines interests (excluding its interest in Tidelands). Marine believes that the term active wells is synonymous with the
term productive wells as defined in Item 1205 of Regulation S-K. While Marine believes that most of the active wells produce both oil and natural gas, Marine is unable to determine the actual
number of wells classified as either oil or natural gas wells without unreasonable effort and expense. See  Difficulty in Obtaining Certain Data.

Drilling Activity. During each of the fiscal years 2018, 2017 and 2016, there were no wells drilled or recompleted in which Marine has
an interest (excluding its interest in Tidelands).

Information regarding net wells or acres is not included since Marine does not own any
working interests.



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Lease Acreage. As of September 1, 2018, Marine had an overriding royalty interest
(including its interest in Tidelands) in 59 different oil and natural gas leases covering an aggregate of 217,056 gross acres. These leases are located in the Central and Western areas of the Gulf of Mexico off the coasts of Louisiana and Texas.
This acreage is presented in the following table:



|                      |  |                  |         | 
|--------------------- |  | ---------------- | ------- | 
|Leases Granted
by(1): |  | ProducingAcreage |        
|United States         |  |                  | 211,526 | 
|State of Texas        |  |                  | 640     | 
|State of Louisiana    |  |                  | 4,890   | 
|                      |  |                  |         | 
|                      |  |                  | 217,056 | 
|                      |  |                  |         | 



|(1) | Leases are typically granted for a term of five years, during which the lease owner must establish commercial
production, or the lease expires. Marines overriding royalty area is determined by a contract that defines the area in which Marine is entitled to receive a royalty interest. In some cases, that area does not cover an entire lease block. In
those cases, Marines royalty interest only applies to the area that lies within the lease. Of the aggregate of 217,056 total gross acres in which Marine has an overriding royalty interest, there are 210 gross acres located on leases that have
commercial production, but the production is not on Marines overriding royalty area within those leases.
|--- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

The
overriding royalty interest owned by Marine is three-fourths of 1% of the working interest held by the Interest Owners. The fractional interest therefore varies from lease to lease. The acreage weighted average of the fractional interest in all
leases, including Marines interest in the leases held by Tidelands, is 0.5776%. The following table presents the acreage breakdown by fractional interests of Marine and Tidelands:



|          |  |            |         |  |          |  |         |  
|--------- |  | ---------- | ------- |  | -------- |  | ------- | -
|Trust     |  | GrossAcres |         |  | Interest | 
|Tidelands |  |            | 17,188  |  |          |  | 1.01137 | %
|Marine    |  |            | 105,672 |  |          |  | 0.7500  | %
|Marine    |  |            | 1,527   |  |          |  | 0.5000  | %
|Marine    |  |            | 40,151  |  |          |  | 0.3750  | %
|Marine    |  |            | 52,518  |  |          |  | 0.2006  | %
|          |  |            |         |  |          |  |         |  
|Summary   |  |            | 217,056 |  |          |  | 0.5776  | %
|          |  |            |         |  |          |  |         |  

Present Activities. As of September 1, 2018, public records indicated that no wells were being
drilled, re-drilled or worked over on tracts in which Marine has an interest. Additionally, public records indicated that operators had not designated any locations for additional operations, which may include
drilling, permits to work over or recomplete a well or other types of operations. There is no assurance that wells will be drilled, and if they are drilled, that they will be successful. Marine is not obligated to provide any fixed and determinable
quantities of oil or natural gas in the future under any existing contracts or agreements.

Difficulty in Obtaining Certain Data.
Marines only activities are the collection and distribution of revenues from overriding royalties on certain oil and natural gas leases in the Gulf of Mexico, pursuant to purchase agreements between Marines predecessors and Gulf and its
transferees. The leasehold working interests that are subject to the rights held by Marine are owned, in most cases, in whole or in part by Arena, or other oil and natural gas exploration and production companies. Certain information with respect to
the particular leases subject to Marines interests, including, but not limited to, (i) reserves, (ii) the availability of oil and natural gas, (iii) the average production cost (lifting cost) per unit, (iv) undeveloped acreage
and (v) net wells and net acres, lies solely within the knowledge of these working interest owners. Marine does not have access to engineering data regarding these leaseholds and believes that such information would have been compiled
principally by or for the working interest owners of these leaseholds, and that such information is unreasonably difficult for Marine to obtain. As a result, Marine believes that unreasonable efforts and expense would be involved in seeking to
obtain all of the information required under Item 102 and Subpart 1200 of Regulation S-K.



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|ITEM 3. | LEGAL PROCEEDINGS
|------- | -----------------

To their knowledge, neither the Trust nor MPC, nor any of their respective properties, is a party to or subject to any material pending
litigation as of the date hereof.



|ITEM 4. | MINE SAFETY DISCLOSURES.
|------- | ------------------------

Not applicable.



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PART II



|ITEM 5. | MARKET FOR REGISTRANTS COMMON EQUITY, RELATED UNITHOLDER MATTERS AND ISSUER PURCHASES OF EQUITY
SECURITIES
|------- | -----------------------------------------------------------------------------------------------------------

The units of beneficial interest in the Trust trade on the Nasdaq Capital Market under the symbol
MARPS. Distributions of cash are made to unitholders quarterly. The following table presents the range of high and low sales prices of the units on the Nasdaq Capital Market by quarter for the past two fiscal years. The per unit amount
of cash distributed to unitholders for each of these quarters is also presented in the table.



|                   |  |             |      |  |                       |   |      |  |  |   |      | 
|------------------ |  | ----------- | ---- |  | --------------------- | - | ---- |  |  | - | ---- | 
|                   |  | Sales Price |      |  | DistributionsPer Unit |  
|Quarter Ending     |  | High        |      |  | Low                   |  
|September 30, 2016 |  | $           | 4.15 |  |                       | $ | 2.97 |  |  | $ | 0.04 | 
|December 31, 2016  |  |             | 6.00 |  |                       |   | 2.91 |  |  |   | 0.09 | 
|March 31, 2017     |  |             | 5.80 |  |                       |   | 3.81 |  |  |   | 0.05 | 
|June 30, 2017      |  |             | 4.55 |  |                       |   | 2.90 |  |  |   | 0.10 | 
|                   |  |             |     
|September 30, 2017 |  | $           | 4.30 |  |                       | $ | 3.10 |  |  | $ | 0.13 | 
|December 31, 2017  |  |             | 4.22 |  |                       |   | 2.83 |  |  |   | 0.05 | 
|March 31, 2018     |  |             | 4.57 |  |                       |   | 3.12 |  |  |   | 0.07 | 
|June 30, 2018      |  |             | 4.85 |  |                       |   | 3.18 |  |  |   | 0.10 | 

The Trust is authorized to issue and has issued 2,000,000 units of beneficial interest. On September 1,
2018, these outstanding units of record were held by 241 unitholders. There were no changes in the number of outstanding units of beneficial interest during the fiscal year ended June 30, 2018.

The Trust must distribute to its unitholders all cash accumulated each quarter, less an amount reserved for accrued liabilities and estimated
future expenses. The amount reserved varies from quarter to quarter and amounted to $66,500 for the distribution paid on June 28, 2018. Such distributions have been made since the Trusts inception and will continue so long as the income
from oil and natural gas royalties exceeds administrative costs.

Distributions primarily fluctuate from quarter to quarter due to changes
in oil and natural gas prices and production quantities. Distributions are determined by the cash available to the Trust on the determination date less reserves for future expenses.

Marine does not maintain any equity compensation plans. The Trust did not repurchase any units of beneficial interest during the quarter ended
June 30, 2018.

While the Trusts Annual Report on Form 10-K (excluding exhibits) for
the fiscal year ended June 30, 2018 is distributed to unitholders, a copy of the Annual Report on Form 10-K (excluding exhibits) is available without charge to interested parties. There will be copying
and mailing charges for copies of any exhibits that are requested. Written requests should be directed to Mr. Ron E. Hooper, Simmons Bank, 2911 Turtle Creek Blvd., Suite 850, Dallas, Texas, 75219.



|ITEM 6. | SELECTED FINANCIAL DATA
|------- | -----------------------

The following table summarizes selected financial information that has been derived from Marines audited consolidated financial
statements. You should read the information set forth below in conjunction with Item 7. Trustees Discussion and Analysis of Financial Condition and Results of Operations and the consolidated financial statements and notes
thereto included elsewhere in this Annual Report on Form 10-K.



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|                                                                               |  |                                                 |      |  |      |   |       |      |  |   |      |  |  |      |       |  |  |   |       | 
|------------------------------------------------------------------------------ |  | ----------------------------------------------- | ---- |  | ---- | - | ----- | ---- |  | - | ---- |  |  | ---- | ----- |  |  | - | ----- | 
|                                                                               |  | Fiscal Year Ended June 30,                      |     
|                                                                               |  | (Dollars in thousands, except per unit amounts) |     
|                                                                               |  | 2018                                            |      |  | 2017 |   |       | 2016 |  |   | 2015 |  |  | 2014 |      
|Consolidated Statements of Distributable Income Selected Data:                 |  |                                                 |      |  |      |   |       |      |  |   |      |  |  |      |       |  |  |   |       | 
|Income:                                                                        |  |                                                 |      |  |      |   |       |      |  |   |      |  |  |      |       |  |  |   |       | 
|Oil and natural gas royalties                                                  |  | $                                               | 863  |  |      | $ | 920   |      |  | $ | 829  |  |  | $    | 1,944 |  |  | $ | 2,956 | 
|Oil and natural gas royalties from affiliate                                   |  |                                                 |     |  |      |   | 26    |      |  |   | 76   |  |  |      | 172   |  |  |   | 170   | 
|Interest and other income                                                      |  |                                                 | 10   |  |      |   | 3     |      |  |   |     |  |  |      |      |  |  |   |      | 
|                                                                               |  |                                                 |      |  |      |   |       |      |  |   |      |  |  |      |       |  |  |   |       | 
|                                                                               |  | $                                               | 873  |  |      | $ | 949   |      |  | $ | 905  |  |  | $    | 2,116 |  |  | $ | 3,126 | 
|                                                                               |  |                                                 |      |  |      |   |       |      |  |   |      |  |  |      |       |  |  |   |       | 
|Expenses:                                                                      |  |                                                 |      |  |      |   |       |      |  |   |      |  |  |      |       |  |  |   |       | 
|General and administrative                                                     |  | $                                               | 211  |  |      | $ | 198   |      |  | $ | 197  |  |  | $    | 227   |  |  | $ | 310   | 
|Federal income taxes of subsidiary                                             |  |                                                 |     |  |      |   |      |      |  |   |     |  |  |      |      |  |  |   |      | 
|                                                                               |  |                                                 |      |  |      |   |       |      |  |   |      |  |  |      |       |  |  |   |       | 
|                                                                               |  |                                                 | 211  |  |      |   | 198   |      |  |   | 197  |  |  |      | 227   |  |  |   | 310   | 
|Distributable income                                                           |  | $                                               | 662  |  |      | $ | 751   |      |  | $ | 708  |  |  | $    | 1,889 |  |  | $ | 2,816 | 
|                                                                               |  |                                                 |      |  |      |   |       |      |  |   |      |  |  |      |       |  |  |   |       | 
|Distributions to unitholders                                                   |  | $                                               | 694  |  |      | $ | 552   |      |  | $ | 683  |  |  | $    | 2,228 |  |  | $ | 2,776 | 
|                                                                               |  |                                                 |      |  |      |   |       |      |  |   |      |  |  |      |       |  |  |   |       | 
|Distributable income per unit                                                  |  | $                                               | 0.33 |  |      | $ | 0.38  |      |  | $ | 0.35 |  |  | $    | 0.94  |  |  | $ | 1.41  | 
|                                                                               |  |                                                 |      |  |      |   |       |      |  |   |      |  |  |      |       |  |  |   |       | 
|Distributions per unit                                                         |  | $                                               | 0.35 |  |      | $ | 0.28  |      |  | $ | 0.34 |  |  | $    | 1.11  |  |  | $ | 1.39  | 
|                                                                               |  |                                                 |      |  |      |   |       |      |  |   |      |  |  |      |       |  |  |   |       | 
|                                                                               | 
|                                                                               |  | At June 30,                                     |     
|                                                                               |  | 2018                                            |      |  | 2017 |   |       | 2016 |  |   | 2015 |  |  | 2014 |      
|Consolidated Statements of Assets, Liabilities and Trust Corpus Selected Data: |  |                                                 |      |  |      |   |       |      |  |   |      |  |  |      |       |  |  |   |       | 
|Total assets                                                                   |  | $                                               | 987  |  |      | $ | 1,019 |      |  | $ | 820  |  |  | $    | 795   |  |  | $ | 1,135 | 
|                                                                               |  |                                                 |      |  |      |   |       |      |  |   |      |  |  |      |       |  |  |   |       | 
|Trust corpus                                                                   |  | $                                               | 987  |  |      | $ | 1,019 |      |  | $ | 820  |  |  | $    | 795   |  |  | $ | 1,135 | 
|                                                                               |  |                                                 |      |  |      |   |       |      |  |   |      |  |  |      |       |  |  |   |       | 



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|ITEM 7. | TRUSTEES DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS
|------- | ----------------------------------------------------------------------------------

Critical Accounting Policies. The financial statements of Marine have been prepared on the modified cash
basis method and are not intended to present Marines financial position and results of operations in conformity with GAAP. Under the modified cash basis method:



| |  |  | Royalty income is recognized when received by Marine.
| | - |  | -----------------------------------------------------



| |  |  | Marines expenses (which include accounting, legal, and other professional fees, Trustees fees and out-of-pocket expenses) are recorded on an actual paid basis. Reserves for liabilities that are contingent or uncertain in amount may also be established if considered
necessary.
| | - |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| |  |  | Distributions to unitholders are recognized when declared by the Trustee of the Trust.
| | - |  | --------------------------------------------------------------------------------------

The financial statements of Marine differ from financial statements prepared in conformity with GAAP because of the following:



| |  |  | Royalty income is recognized in the month received rather than in the month of production.
| | - |  | ------------------------------------------------------------------------------------------



| |  |  | Reserves may be established for certain contingencies that would not be recorded under GAAP.
| | - |  | --------------------------------------------------------------------------------------------



| |  |  | Expenses are recorded in the month paid rather than in the month incurred.
| | - |  | --------------------------------------------------------------------------

This comprehensive basis of accounting corresponds to the accounting principles permitted for royalty trusts by the SEC as specified by Staff
Accounting Bulletin Topic 12:E, Financial Statements of Royalty Trusts.

The preparation of financial statements in conformity with the
modified cash basis method of accounting requires the Trustee to make various estimates and assumptions that affect the reported amount of liabilities at the date of the financial statements and the reported amount of expenses during the reporting
period. Actual results may differ from such estimates.

Effective October 19, 2017, Simmons First National Corporation
(SFNC) completed its acquisition of First Texas BHC, Inc., the parent company of Southwest Bank. SFNC is the parent of Simmons Bank. SFNC merged Southwest Bank, the former corporate Trustee of the Trust, with Simmons Bank effective
February 20, 2018. The defined term Trustee as used herein shall refer to Southwest Bank for periods from May 30, 2014 through February 19, 2018 and to Simmons Bank for periods on and after February 20, 2018.

Results of Operations. Marines revenues are derived from the oil and natural gas production activities of third parties.
Marines revenues and distributions fluctuate from period to period based upon factors beyond Marines control, including, without limitation, the number of leases subject to Marines interests, the number of productive wells drilled
on leases subject to Marines interests, the level of production over time from such wells and the prices at which the oil and natural gas from such wells are sold.

Marines results of operations are significantly impacted by oil and natural gas prices and the quantity of oil and natural gas
production. Oil and natural gas prices have historically experienced significant volatility. Marine is not permitted to manage its commodity price risk through the use of fixed price contracts or financial derivatives.

Marines income consists primarily of oil and natural gas royalties and is based on the value at the well of its percentage interest in
oil and natural gas sold without reduction for any of the expenses of production. Value at the well for oil means the purchasers selling price at its receiving point onshore, less the cost of transportation from the offshore lease
to the onshore receiving point. Value at the well for natural gas means the selling price less the cost of compression, dehydration and transportation from the lease to the delivery point of the pipeline transporting the product to
market. In general, value at the well is determined on the basis of the selling price of oil, natural gas and other minerals produced, saved and sold, or at wellhead prices determined by industry standards, where the selling price does not reflect
value at the well. In the event an agreement is not arms-length in nature, the value is based upon current market prices.



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Summary Review. In general, Marine receives royalties two months after oil production and
three months after natural gas production. The June 2018 distribution of $0.092879 per unit increased from the March 2018 distribution of $0.074791 per unit. As disclosed in a press release dated August 21, 2018, the September 2018 distribution
of $0.090111 per unit will be a slight decrease from the June 2018 distribution of $0.092879 per unit.

Marines distributable income
for fiscal 2018 amounted to $661,919 or $0.33 per unit, as compared to $751,506, or $0.38 per unit, in fiscal 2017, and $708,142, or $0.35 per unit, in fiscal 2016. Distributions to unitholders are calculated and paid out net of reserve for future
expenses, which are estimated by the Trustee on a quarterly basis.

These results also include income from the Trusts interest in
Tidelands, which amounted to $56 for fiscal 2018, $26,355 for fiscal 2017 and $75,946 for fiscal 2016. Income from Tidelands contributed approximately 0.01% of Marines royalty income for fiscal 2018 as compared to 3% of Marines royalty
income in fiscal 2017 and to 8% of Marines royalty income in fiscal 2016.

The following table shows the number of wells drilled or
recompleted on leases in which Marine has an interest (including its interest in Tidelands) and the number of active wells at the end of each of the past three fiscal years.



|                                     |  |                           |     |  |      |  |     |      |  |  |     | 
|------------------------------------ |  | ------------------------- | --- |  | ---- |  | --- | ---- |  |  | --- | 
|                                     |  | Fiscal Year EndedJune 30, |    
|                                     |  | 2018                      |     |  | 2017 |  |     | 2016 | 
|Wells Drilled or Recompleted (Gross) |  |                           |    |  |      |  |    |      |  |  |    | 
|Active Wells (Gross)                 |  |                           | 201 |  |      |  | 201 |      |  |  | 201 | 

The following table and related discussion and analysis shows the royalty income, the net quantities sold, and
the average price received for oil and natural gas during fiscal 2018, 2017 and 2016, excluding the Trusts interest in Tidelands.



|                                           |  |                            |         |  |      |   |         |      |  |   |         | 
|------------------------------------------ |  | -------------------------- | ------- |  | ---- | - | ------- | ---- |  | - | ------- | 
|                                           |  | Fiscal Year Ended June 30, |        
|                                           |  | 2018                       |         |  | 2017 |   |         | 2016 | 
|Income from:                               |  |                            |         |  |      |   |         |      |  |   |         | 
|Oil royalties                              |  | $                          | 798,650 |  |      | $ | 830,861 |      |  | $ | 709,677 | 
|Natural gas royalties                      |  | $                          | 64,285  |  |      | $ | 89,513  |      |  | $ | 119,861 | 
|                                           |  |                            |         |  |      |   |         |      |  |   |         | 
|Totals                                     |  | $                          | 862,935 |  |      | $ | 920,374 |      |  | $ | 829,538 | 
|                                           |  |                            |        
|Net quantities sold:                       |  |                            |         |  |      |   |         |      |  |   |         | 
|Oil (bbls)                                 |  |                            | 15,138  |  |      |   | 18,439  |      |  |   | 15,841  | 
|Natural gas (mcf)                          |  |                            | 20,664  |  |      |   | 40,867  |      |  |   | 56,719  | 
|                                           |  |                            |        
|Average price:                             |  |                            |         |  |      |   |         |      |  |   |         | 
|Oil (per bbl) (1)                          |  | $                          | 50.76   |  |      | $ | 45.06   |      |  | $ | 44.80   | 
|Natural gas, net of expenses (per mcf) (1) |  | $                          | 3.10    |  |      | $ | 2.19    |      |  | $ | 2.11    | 



|(1) | These amounts are net of the cost of transportation from offshore leases to onshore receiving points.
|--- | -----------------------------------------------------------------------------------------------------

Fiscal Year 2018 Compared to Fiscal Year 2017. During fiscal 2018, Marine received approximately 93% of
its royalty income from the sale of oil and 7% of its royalty income from the sale of natural gas, as compared to approximately 90% of its royalty income from the sale of oil and 10% of its royalty income from the sale of natural gas in fiscal year
2017. Income from oil and natural gas royalties in fiscal 2018 decreased approximately 6% from fiscal 2017, primarily due to a decrease in production of oil and natural gas, offset in part by an increase in prices realized for oil and natural gas.



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Revenue from oil royalties amounted to $798,650 in fiscal 2018, a decrease from the $830,861realized in fiscal 2017. The average price realized for a barrel of oil increased to $50.76 in fiscal 2018 from the $45.06realized in fiscal 2017. In fiscal 2018, oil production decreased to 15,138 bbls from the 18,439 bbls produced in
fiscal 2017.

Revenue from natural gas royalties amounted to $64,285 in fiscal 2018, a decrease from the $89,513 realized in fiscal 2017.
In fiscal 2018, the average price per mcf of natural gas increased to $3.10 from the $2.19 realized in fiscal 2017. In fiscal 2018, natural gas production decreased to 20,664 mcf from the 40,867 mcf produced in fiscal 2017.

General and administrative expenses for fiscal 2018 amounted to $210,723,an increase from the $198,032 recorded in fiscal 2017, due to
an increase in investor costs, professional fees, operation data services and transfer agent fees, offset in part by a decrease in printing expenses.

Fiscal Year 2017 Compared to Fiscal Year 2016. During fiscal 2017, Marine received approximately 90% of its royalty income from the
sale of oil and 10% of its royalty income from the sale of natural gas, as compared to approximately 86% of its royalty income from the sale of oil and 14% of its royalty income from the sale of natural gas in fiscal 2016. Income from oil and
natural gas royalties in fiscal 2017 increased approximately 11% from fiscal 2016, primarily due to an increase in the production of oil and an increase in prices realized for oil and natural gas, offset in part by a decrease in the production of
natural gas.

Revenue from oil royalties amounted to $830,861 in fiscal 2017, an increase from the $709,677 realized in fiscal 2016. The
average price realized for a barrel of oil increased to $45.06from the $44.80realized in fiscal 2016. In fiscal 2017, oil production increased to 18,439bbls from the 15,841 bbls produced in fiscal 2016.

Revenue from natural gas royalties amounted to $89,513 in fiscal 2017, a decrease from the $119,861 realized in fiscal 2016. In fiscal 2017,
the average price per mcf of natural gas increased to $2.19from the $2.11 realized in fiscal 2016. In fiscal 2017, natural gas production decreased to 40,867mcf from the 56,719 mcf produced in fiscal 2016.

General and administrative expenses for fiscal 2017 amounted to $198,032,an increase from the $197,492 recorded in fiscal 2016, due to
an increase in professional fees and expenses, offset in part by a decrease in operation data services and transfer agent fees.

Capital Resources and Liquidity. The Trusts Indenture (and the charter and by-laws of
MPC) expressly prohibits the operation of any kind of trade or business. Due to the limited purpose of the Trust as stated in the Trusts Indenture, there is no requirement for capital. Its only obligation is to distribute to unitholders the
distributable income actually collected.

As an administrator of oil and natural gas royalty properties, the Trust collects income
monthly, pays expenses of administration and disburses all distributable income collected to its unitholders each quarter, less an amount reserved for accrued liabilities and estimated future expenses. Because all of Marines revenues are
invested in liquid funds pending distribution, Marine does not experience liquidity problems.

Marines oil and natural gas
properties are depleting assets and are not being replaced due to the prohibition against these investments. These restrictions, along with other factors, allow the Trust to be treated as a non-taxable grantor
trust for U.S. Federal income tax purposes. Accordingly, all of Marines income and deductions should flow through to its unitholders on a proportionate basis. MPC will owe U.S. Federal (and state) income taxes with respect to its income after
deducting statutory depletion. MPCs income specifically excludes 98% of oil and natural gas royalties collected by MPC, which are retained by and delivered to the Trust in respect of the Trusts net profits interest.

The Trust does not currently have any long term contractual obligations, other than the obligation to make distributions to unitholders
pursuant to the Indenture. The Trust does not maintain any off-balance sheet arrangements within the meaning of Item 303 of Regulation S-K.



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Forward-Looking Statements. The statements discussed in this Annual Report on Form 10-K regarding Marines future financial performance and results of operations, and other statements that are not historical facts, are forward-looking statements as defined in Section 27A of the
Securities Act of 1933, as amended and Section 21E of the Securities Exchange Act of 1934, as amended (the Exchange Act). Marine uses the words may, expect, anticipate, estimate,
believe, continue, intend, plan, budget, or other similar words to identify forward-looking statements. All forward-looking statements speak only as of the date on which they are made. You
should read statements that contain these words carefully because they discuss future expectations, contain projections of Marines financial condition, and/or state other forward-looking information. Actual results may differ from
expected results because of factors, risks and uncertainties including, but not limited to, the following: reductions in prices or demand for oil and natural gas, which might then lead to decreased production or impair Marines ability to make
distributions; reductions in production due to the depletion of existing wells or disruptions in service, which may be caused by storm damage to production facilities, blowouts or other production accidents, or geological changes such as cratering
of productive formations; changes in regulations; general economic conditions; actions and policies of petroleum producing nations; other changes in domestic and international energy markets; the resignation of the Trustee; and the expiration,
termination or release of leases subject to Marines interests. Events may occur in the future that Marine is unable to accurately predict, or over which it has no control. If one or more of these uncertainties as well as other risks of which
we are not aware materialize, or if underlying assumptions prove incorrect, actual outcomes may vary materially from those contained in the forward-looking statements included in this Annual Report on Form
10-K.

Website.Marine has an Internet website and has made available its Annual
Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, and amendments to such reports, filed or
furnished pursuant to Section 13(a) or 15(d) of the Exchange Act, at www.marps-marine.com. Each of these reports will be posted on this website as soon as reasonably practicable after such report is electronically filed with or furnished to the
SEC.



|ITEM 7A. | QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK
|-------- | ----------------------------------------------------------

As described elsewhere herein, Marines only function is to collect overriding royalties from leases operated by others and distribute
those royalties to unitholders after paying the cost of collection and administration. Marines income is highly dependent on the prices realized from the sale of oil and natural gas and the quantities of production from wells in which it has a
royalty interest. Oil and natural gas prices have historically experienced significant volatility. Marine is not permitted to manage its commodity price risk through the use of fixed price contracts or financial derivatives.

Due to the short length of time between receipts and disbursements, cash held by the Trust is held in a
non-interest bearing trust account, and there is no material interest rate risk. Oil and natural gas royalties received by MPC prior to delivery of the 98% net profits interest to the Trust are held in money
market accounts that invest in U.S. Treasury securities and are considered not subject to interest rate risk. The corpus of MPC is held in either money market accounts or U.S. Treasury or agency securities that are held to maturity. Funds held in
money market accounts and U.S. Treasury securities that mature in less than one year are considered not subject to interest rate risk.



|ITEM 8. | FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA
|------- | -------------------------------------------

The financial statements listed in the following index, together with the related notes and the report of Weaver and Tidwell, L.L.P.,
independent registered public accounting firm, are presented on the following pages and are incorporated by reference herein.



|                                                                                                            |  |      |    | 
|----------------------------------------------------------------------------------------------------------- |  | ---- | -- | 
|                                                                                                            |  | Page |   
|Report of Independent Registered Public Accounting Firm                                                     |  |      | 23 | 
|Financial Statements:                                                                                       |  |      |    | 
|Consolidated Statements of Assets, Liabilities and Trust Corpus as of June 30,
 2018 and 2017               |  |      | 24 | 
|Consolidated Statements of Distributable Income for the Fiscal Years Ended June 30,
 2018, 2017 and 2016    |  |      | 25 | 
|Consolidated Statements of Changes in Trust Corpus for the Fiscal Years Ended
 June 30, 2018, 2017 and 2016 |  |      | 26 | 
|Notes to Consolidated Financial Statements                                                                  |  |      | 27 | 



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See also Item 15. Exhibits and Financial Statement Schedules of this
Annual Report on Form 10-K for further information concerning Marines financial statements.

All schedules have been omitted because they are either not required, not applicable or the required information is included in the
consolidated financial statements and notes thereto.



|ITEM 9. | CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND FINANCIAL DISCLOSURE
|------- | ------------------------------------------------------------------------------------

Not applicable.



|ITEM 9A. | CONTROLS AND PROCEDURES
|-------- | -----------------------

Effectiveness of Disclosure Controls and Procedures

As of June 30, 2018, the Trustee carried out an evaluation of the effectiveness of the design and operation of the Trusts disclosure
controls and procedures pursuant to Rules 13a-15(e) and 15d-15(e) of the Exchange Act. Based upon that evaluation, the Trustee concluded that Marines disclosure
controls and procedures were effective as of June 30, 2018.

Changes in Internal Control Over Financial Reporting

There have not been any changes in Marines internal control over financial reporting during the fourth quarter of fiscal 2018 that have
materially affected, or are reasonably likely to materially affect, Marines internal control over financial reporting.

Trustees Report on
Internal Control Over Financial Reporting

The Trustee is responsible for establishing and maintaining adequate internal control over
financial reporting, as such term is defined in Rule 13a-15(f) or Rule 15d-15(f) under the Exchange Act. The Trustee conducted an evaluation of the effectiveness of
Marines internal control over financial reporting based on the criteria established in Internal Control-Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission. Based on the
Trustees evaluation under the Internal Control-Integrated Framework, the Trustee concluded that Marines internal control over financial reporting was effective as of June 30, 2018. This Annual Report on Form 10-K does not include an attestation report of Marines registered public accounting firm regarding internal control over financial reporting since the Trustees report was not subject to attestation by
Marines registered public accounting firm pursuant to an exemption for smaller reporting companies pursuant to Section 404(c) of the Sarbanes-Oxley Act of 2002.



|ITEM 9B. | OTHER INFORMATION
|-------- | -----------------

None.



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##### Table of Contents

PART III



|ITEM 10. | DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE
|-------- | ------------------------------------------------------

Directors and Officers.The Trust is a trust created under the laws of the State of Texas. The Trusts Indenture does not provide
for directors or officers or the election or appointment of directors or officers. Under the Indenture, Simmons Bank, serves as the Trustee.

Section16(a) Beneficial Ownership Reporting Compliance. The Trust has no directors or officers and is not aware of
any beneficial owner of more than ten percent of the units of beneficial interest who failed to file reports required by Section 16(a) under the Exchange Act on a timely basis during the fiscal year ended June 30, 2018.

Code of Ethics.Because the Trust has no employees, it does not have a code of ethics. Employees of the Trustee must comply with the
Trustees code of ethics, a copy of which will be made available to unitholders without charge, upon request by appointment at Simmons Bank, 2911 Turtle Creek Blvd., Suite 850, Dallas, Texas 75219.

Committees.The Trust has no directors and therefore has no audit committee or audit committee financial expert and no nominating
committee or compensation committee.



|ITEM 11. | EXECUTIVE COMPENSATION
|-------- | ----------------------

The Trust has no directors or officers and is administered by the Trustee. Accordingly, the Trust does not have a compensation committee or
maintain any equity compensation plans, and there are no units reserved for issuance under any such plans. During the past three fiscal years, the Trust paid or accrued fees to the Trustee, as set forth below.



|                                                  |  |            |          |  |                             |    |              | 
|------------------------------------------------- |  | ---------- | -------- |  | --------------------------- | -- | ------------ | 
|Name of Individual or Entity                      |  | FiscalYear |          |  | Other AnnualCompensation(1) |   
|Simmons Bank, Trustee (2)
Southwest Bank, Trustee |  |            | 20182018 |  |                             | $$ | 14,00014,000 | 
|Southwest Bank, Trustee                           |  |            | 2017     |  |                             | $  | 28,000       | 
|Southwest Bank, Trustee                           |  |            | 2016     |  |                             | $  | 28,000       | 



|(1) | Under the Indenture, the Trustee is entitled to reasonable and customary fees and compensation for its
services.
|--- | ----------------------------------------------------------------------------------------------------------------

|(2) | Simmons Bank has served as Trustee since February 20, 2018, the effective date of its merger with
Southwest Bank.
|--- | -----------------------------------------------------------------------------------------------------------------



|ITEM 12. | SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT AND RELATED UNITHOLDER MATTERS
|-------- | ---------------------------------------------------------------------------------------------

The following table sets forth the persons known to the Trust who beneficially own more than five percent of the
outstanding units of beneficial interest as of September 1, 2018, based solely on the Trusts review of information filed with the SEC and information provided by such persons:



|                                                           |  |                                        |               |  |                |  |      |  
|---------------------------------------------------------- |  | -------------------------------------- | ------------- |  | -------------- |  | ---- | -
|Name and Address                                           |  | Amount andNature ofBeneficialOwnership |               |  | PercentofClass | 
|Robert H. Paslay
1007 Gasserway Circle
Brentwood, TN 37027 |  |                                        | 213,837 units |  |                |  | 10.7 | %
|                                                           |  |                                       
|Patricia Martin
110 Woodbine Place
Missoula, MT 59803      |  |                                        | 174,529 units |  |                |  | 8.7  | %



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There are no executive officers or directors of the Trust. The Trustee does not beneficially own
any units of beneficial interest. The Trust does not maintain any equity compensation plans and the Trust has not repurchased any units during the fourth quarter of fiscal 2018. The Trustee knows of no arrangements the operation of which may at a
subsequent date result in a change of control of the Trust.



|ITEM 13. | CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS, AND DIRECTOR INDEPENDENCE
|-------- | -------------------------------------------------------------------------

None.



|ITEM 14. | PRINCIPAL ACCOUNTING FEES AND SERVICES
|-------- | --------------------------------------

Fees for services performed by Weaver and Tidwell, L.L.P. for the fiscal years ended June 30, 2018 and 2017 were as follows:



|                   |  |         |  |        
|------------------ |  | ------- |  | -------
|                   |  | 2018    |  | 2017   
|Audit Fees         |  | $50,000 |  | $50,000
|Audit-Related Fees |  |        |  |       
|Tax Fees           |  |        |  |       
|All Other Fees     |  |        |  |       

As referenced in Item10. Directors, Executive Officers and Corporate
Governance above, the Trust has no audit committee, and as a result, has no audit committee pre-approval policy with respect to fees paid to its independent registered public accounting firm.



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PART IV



|ITEM 15. | EXHIBITS, FINANCIAL STATEMENT SCHEDULES
|-------- | ---------------------------------------

(a) Financial Statements  see Item 8. Financial Statements and Supplementary Data above.

The consolidated financial statements of Tidelands, together with the related notes and the report of Weaver and Tidwell, L.L.P., independent
registered public accounting firm, as contained in its Annual Report on Form 10-K for the year ended December 31, 2017 filed with the SEC and filed herewith as Exhibit 99.1, are hereby incorporated herein
by reference.

(b) Exhibits:



|      |  |                                                                                                                                                                                                                                          
|----- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|4.1   |  | Indenture, as amended on December 8, 2000, of Marine Petroleum Trust, filed as Exhibit 4.1 to the Annual Report on Form 10-K of Marine for the fiscal year ended June 30, 2001 (File No.000-08565), and incorporated by reference herein.
|      | 
|21.1  |  | Subsidiaries of Marine, filed as Exhibit 21.1 to the Annual Report on Form 10-K of Marine for the fiscal
 year ended June 30, 2002 (File No.000-08565), and incorporated by reference herein.                                            
|      | 
|31.1* |  | Certification of the Corporate Trustee pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.                                                                                                                                        
|      | 
|32.1* |  | Certification of the Corporate Trustee pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.                                                                                                                                        
|      | 
|99.1* |  | Consolidated financial statements of Tidelands Royalty Trust B for the year ended December 
31, 2017, and report of Weaver and Tidwell, L.L.P., independent registered public accounting firm.                                         



|* | Filed herewith.
|- | ---------------

(c) Financial Statement Schedules  All required schedules are included in the financial statements included in this Annual Report on
Form 10-K.



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REPORT OF INDEPENDENT REGISTERED

PUBLIC ACCOUNTING FIRM

The Trustee and
Unitholders

Marine Petroleum Trust and Subsidiary

Opinion on the Consolidated Financial Statements

We have
audited the accompanying consolidated statements of assets, liabilities, and trust corpus of Marine Petroleum Trust and Subsidiary (the Trust) as of June 30, 2018 and 2017, and the related consolidated statements of distributable income and
changes in trust corpus for each of the three years in the period ended June 30, 2018, and the related notes (collectively referred to as the consolidated financial statements). In our opinion, the consolidated financial statements
present fairly, in all material respects, the assets, liabilities, and trust corpus of the Trust as of June 30, 2018 and 2017, and the distributable income and changes in trust corpus for each of the three years in the period ended
June 30, 2018, in conformity with the modified cash basis of accounting, which is a comprehensive basis of accounting other than accounting principles generally accepted in the United States of America.

As described in Note 2 to the consolidated financial statements, these consolidated financial statements were prepared on a modified cash basis of accounting,
which is a comprehensive basis of accounting other than accounting principles generally accepted in the United States of America.

Basis for Opinion

These consolidated financial statements are the responsibility of the Trustee. Our responsibility is to express an opinion on these consolidated
financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Trust in accordance
with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our
audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to
error or fraud. The Trust is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial
reporting but not for the purpose of expressing an opinion on the effectiveness of the entitys internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or
fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the
accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. We believe that our audits provide a reasonable basis for our opinion.

/s/ WEAVER AND TIDWELL, L.L.P.

We have served as the
Trusts auditor since 2011.

Dallas, Texas

September 28, 2018



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MARINE PETROLEUM TRUST AND SUBSIDIARY

CONSOLIDATED STATEMENTS OF ASSETS, LIABILITIES AND TRUST CORPUS

As of June 30, 2018 and 2017



|                                                                                                          |  |              |         |  |              |   |           | 
|--------------------------------------------------------------------------------------------------------- |  | ------------ | ------- |  | ------------ | - | --------- | 
|                                                                                                          |  | June 30,2018 |         |  | June 30,2017 |  
|Assets                                                                                                    |  |              |         |  |              |   |           | 
|Current assets:                                                                                           |  |              |         |  |              |   |           | 
|Cash and cash equivalents                                                                                 |  | $            | 984,216 |  |              | $ | 1,016,681 | 
|Federal income taxes refundable                                                                           |  |              | 2,800   |  |              |   | 2,800     | 
|Producing oil and gas properties                                                                          |  |              | 7       |  |              |   | 7         | 
|                                                                                                          |  |              |         |  |              |   |           | 
|Total assets                                                                                              |  | $            | 987,023 |  |              | $ | 1,019,488 | 
|                                                                                                          |  |              |         |  |              |   |           | 
|                                                                                                          |  |             
|Liabilities and Trust Corpus                                                                              |  |              |         |  |              |   |           | 
|                                                                                                          |  |             
|Current liabilities:                                                                                      |  |              |         |  |              |   |           | 
|Federal income taxes payable                                                                              |  |              |        |  |              |   |          | 
|                                                                                                          |  |              |         |  |              |   |           | 
|Total current liabilities                                                                                 |  | $            |        |  |              | $ |          | 
|                                                                                                          |  |              |         |  |              |   |           | 
|                                                                                                          |  |             
|Trust Corpus  authorized 2,000,000 units of beneficial interest, issued 2,000,000 units at
nominal value |  |              | 987,023 |  |              |   | 1,019,488 | 
|                                                                                                          |  |              |         |  |              |   |           | 
|                                                                                                          |  | $            | 987,023 |  |              | $ | 1,019,488 | 
|                                                                                                          |  |              |         |  |              |   |           | 

See accompanying notes to consolidated financial statements.



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MARINE PETROLEUM TRUST AND SUBSIDIARY

CONSOLIDATED STATEMENTS OF DISTRIBUTABLE INCOME

For The Fiscal Years Ended June 30,



|                                                 |  |      |           |  |      |   |           |      |  |   |           | 
|------------------------------------------------ |  | ---- | --------- |  | ---- | - | --------- | ---- |  | - | --------- | 
|                                                 |  | 2018 |           |  | 2017 |   |           | 2016 | 
|Income:                                          |  |      |           |  |      |   |           |      |  |   |           | 
|Oil and natural gas royalties                    |  | $    | 862,935   |  |      | $ | 920,374   |      |  | $ | 829,538   | 
|Oil and natural gas royalties from affiliate     |  |      | 56        |  |      |   | 26,355    |      |  |   | 75,946    | 
|Interest and other income                        |  |      | 9,651     |  |      |   | 2,809     |      |  |   | 150       | 
|                                                 |  |      |           |  |      |   |           |      |  |   |           | 
|Total income                                     |  | $    | 872,642   |  |      | $ | 949,538   |      |  | $ | 905,634   | 
|                                                 |  |      |          
|Expenses:                                        |  |      |           |  |      |   |           |      |  |   |           | 
|General and administrative                       |  |      | 210,723   |  |      |   | 198,032   |      |  |   | 197,492   | 
|                                                 |  |      |           |  |      |   |           |      |  |   |           | 
|Distributable income before Federal income taxes |  |      | 661,919   |  |      |   | 751,506   |      |  |   | 708,142   | 
|Federal income taxes of subsidiary               |  |      |          |  |      |   |          |      |  |   |          | 
|                                                 |  |      |           |  |      |   |           |      |  |   |           | 
|Distributable income                             |  | $    | 661,919   |  |      | $ | 751,506   |      |  | $ | 708,142   | 
|                                                 |  |      |           |  |      |   |           |      |  |   |           | 
|Distributable income per unit                    |  | $    | 0.33      |  |      | $ | 0.38      |      |  | $ | 0.35      | 
|                                                 |  |      |           |  |      |   |           |      |  |   |           | 
|Distributions per unit                           |  | $    | 0.35      |  |      | $ | 0.28      |      |  | $ | 0.34      | 
|                                                 |  |      |           |  |      |   |           |      |  |   |           | 
|Units outstanding                                |  |      | 2,000,000 |  |      |   | 2,000,000 |      |  |   | 2,000,000 | 
|                                                 |  |      |           |  |      |   |           |      |  |   |           | 

See accompanying notes to consolidated financial statements.



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MARINE PETROLEUM TRUST AND SUBSIDIARY

CONSOLIDATED STATEMENTS OF CHANGES IN TRUST CORPUS

For The Fiscal Years Ended June 30,



|                                |  |      |           |   |      |   |           |      |  |   |          |  
|------------------------------- |  | ---- | --------- | - | ---- | - | --------- | ---- |  | - | -------- | -
|                                |  | 2018 |           |   | 2017 |   |           | 2016 | 
|Trust corpus, beginning of year |  | $    | 1,019,488 |   |      | $ | 820,188   |      |  | $ | 795,072  |  
|Distributable income            |  |      | 661,919   |   |      |   | 751,506   |      |  |   | 708,142  |  
|Distributions to unitholders    |  |      | (694,384  | ) |      |   | (552,206  | )    |  |   | (683,026 | )
|                                |  |      |           |   |      |   |           |      |  |   |          |  
|Trust corpus, end of year       |  | $    | 987,023   |   |      | $ | 1,019,488 |      |  | $ | 820,188  |  
|                                |  |      |           |   |      |   |           |      |  |   |          |  

See accompanying notes to consolidated financial statements.



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MARINE PETROLEUM TRUST AND SUBSIDIARY

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(1) Summary of Significant Accounting Policies

(a) General

Marine
Petroleum Trust (the Trust) was established on June 1, 1956 with the transfer of property to the Trust consisting of certain contract rights, units of beneficial interest and common stock in exchange for units of beneficial interest
in the Trust. The contract rights entitled the Trust to receive an overriding royalty interest in oil, natural gas and other mineral leasehold interests acquired by Gulf Oil Corporation, now Chevron U.S.A., Inc. (Chevron), a subsidiary
of Chevron Corporation, in certain areas of the Gulf of Mexico prior to January 1, 1980.

The Trust must distribute to its
unitholders all cash accumulated each quarter, less an amount reserved for accrued liabilities and estimated future expenses. The Trust and its subsidiary cannot engage in a trade or business. Funds held by Marine Petroleum Corporation, a wholly
owned subsidiary of the Trust, (MPC, and collectively with the Trust, Marine) pending distribution to the Trust are invested in U.S. Treasury and agency bonds.

The unitholders assigned their contract rights offshore of Louisiana to MPC reserving a 98% net profits interest to themselves. The net
profits interest contract was transferred to the Trust along with the other properties. The Trust is authorized to pay expenses of MPC should it be necessary.

The Trust is to continue until June 1, 2021, or until such later date as holders of the units owning a majority of the outstanding units
may designate, but in any event, not more than 20 years from such designation. However, the unitholders owning eighty percent (80%) or more of the outstanding units may terminate the Trust on any date.

(b) Principles of Consolidation

The consolidated financial statements include the Trust and its wholly owned subsidiary, MPC. All material intercompany accounts and
transactions have been eliminated upon consolidation.

(c) Producing Oil and Gas Properties

At the time the Trust was established, no determinable market value was available for the assets transferred to the Trust; consequently,
nominal values were assigned. Accordingly, no allowance for depletion has been included. All income from oil and natural gas royalties relate to proved developed oil and natural gas reserves.

(d) U.S. Federal Income Taxes

No provision has been made for U.S. Federal income taxes on the Trusts income since such taxes are the liability of the unitholders.

U.S. Federal income taxes have been provided on the income of MPC (which specifically excludes the 98% net profits interest to be retained by
and delivered to the Trust), after deducting statutory depletion. MPC uses the cash method of reporting for U.S. Federal income taxes.

The primary difference between the actual tax expense of MPC and the expected tax expense is due to the fact that only 2% of MPCs income
(i.e., excluding the 98% net profits interest retained by, and delivered to, the Trust) is subject to U.S. Federal income tax.

Tax
positions taken by the Trust related to the Trusts pass-through status and federal state tax positions have been reviewed, and the Trustee is of the opinion that material positions taken would more likely than not be sustained upon an
examination. In accordance with the Trusts basis of accounting discussed in Note 2, the Trust would only recognize the impact of tax positions that were not upheld at the time of payment. As of June 30, 2018, the Trusts tax years
2014 through 2017 remain subject to examination.



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##### Table of Contents

MPC recognizes interest and penalties related to unrecognized tax benefits in income tax expense.

(e) Credit Risk Concentration and Cash Equivalents

Financial instruments which potentially subject Marine to concentrations of credit risk are primarily investments in cash equivalents, U.S.
Treasury and agency bonds. The Trust and MPC place their cash investments with financial institutions or companies that the Trustee considers credit worthy and limit the amount of credit exposure from any one financial institution.

Marine had cash and cash equivalents of $984,216 and $1,016,681 at June 30, 2018 and 2017, respectively, which consisted of cash
deposits, U.S. Treasury and agency bonds and money market accounts.

(f) Use of Estimates

The preparation of financial statements in conformity with the modified cash basis method of accounting requires the Trustee to make various
estimates and assumptions that affect the reported amount of liabilities at the date of the financial statements and the reported amount of expenses during the reporting period. Actual results may differ from such estimates.

(g) Distributable Income per Unit and Distributions

Distributable income per unit is determined by dividing distributable income by the number of units of beneficial interest outstanding during
the period. Distributions to unitholders are calculated and paid out net of reserve for future expenses, which are estimated by the Trustee on a quarterly basis.

(h) Significant Royalty Sources

Percent of royalty revenue received by Marine from producers is summarized as follows:



|                                   |  |                           |     |   |      |  |     |      |  |  |     |  
|---------------------------------- |  | ------------------------- | --- | - | ---- |  | --- | ---- |  |  | --- | -
|                                   |  | Fiscal Year EndedJune 30, |    
|Company                            |  | 2018                      |     |   | 2017 |  |     | 2016 | 
|Arena Energy, LP                   |  |                           | 90  | % |      |  | 63  | %    |  |  | 21  | %
|Chevron USA, Inc.                  |  |                           | 6   | % |      |  | 26  | %    |  |  | 59  | %
|Fieldwood Energy LLC               |  |                           | 4   | % |      |  | 9   | %    |  |  | 8   | %
|Walter Energy, Inc.                |  |                           |    |   |      |  | 1   | %    |  |  | 5   | %
|Anglo Suisse Offshore Partners LLP |  |                           |    |   |      |  |    |      |  |  | 3   | %
|Century Energy Ltd.                |  |                           |    |   |      |  |    |      |  |  | 3   | %
|Others                             |  |                           |    |   |      |  | 1   | %    |  |  | 1   | %
|                                   |  |                           |     |   |      |  |     |      |  |  |     |  
|                                   |  |                           | 100 | % |      |  | 100 | %    |  |  | 100 | %

(2) Basis of Accounting

The financial statements of Marine have been prepared on the modified cash basis method and are not intended to present financial position and
results of operations in conformity with accounting principles generally accepted in the United States of America (GAAP). Under the modified cash basis method:



| |  |  | Royalty income is recognized when received by Marine.
| | - |  | -----------------------------------------------------



| |  |  | Marines expenses (which include accounting, legal, and other professional fees, Trustees fees and out-of-pocket expenses) are recorded on an actual paid basis. Reserves for liabilities that are contingent or uncertain in amount may also be established if considered
necessary.
| | - |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| |  |  | Distributions to unitholders are recognized when declared by the Trustee of the Trust.
| | - |  | --------------------------------------------------------------------------------------



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The financial statements of Marine differ from financial statements prepared in conformity with
GAAP because of the following:



| |  |  | Royalty income is recognized in the month received rather than in the month of production.
| | - |  | ------------------------------------------------------------------------------------------



| |  |  | Reserves may be established for contingencies that would not be recorded under GAAP.
| | - |  | ------------------------------------------------------------------------------------



| |  |  | Expenses are recorded in the month paid rather than in the month incurred.
| | - |  | --------------------------------------------------------------------------

This comprehensive basis of accounting corresponds to the accounting principles permitted for royalty trusts by the Securities and Exchange
Commission (the SEC), as specified by Staff Accounting Bulletin Topic 12:E, Financial Statements of Royalty Trusts.

(3) Investment in
Affiliate  Tidelands Royalty Trust B

At June 30, 2018 and 2017, the Trust owned 32.6% of the outstanding units
of beneficial interest in Tidelands Royalty Trust B (Tidelands). The 452,366 units owned by the Trust had a market value of $330,227 and $769,022 at June 30, 2018 and 2017, respectively, based on the closing price of
Tidelands units on the OTC Bulletin Board on such dates.

The following summary financial statements have been derived from the
unaudited consolidated financial statements of Tidelands:

TIDELANDS CONSOLIDATED STATEMENTS OF ASSETS, LIABILITIES AND TRUST CORPUS



|                                                                                                    |  |              |         |  |              |   |         | 
|--------------------------------------------------------------------------------------------------- |  | ------------ | ------- |  | ------------ | - | ------- | 
|                                                                                                    |  | June 30,2018 |         |  | June 30,2017 |  
|Assets                                                                                              |  |              |         |  |              |   |         | 
|                                                                                                    |  |             
|Current assets:                                                                                     |  |              |         |  |              |   |         | 
|Cash and cash equivalents                                                                           |  | $            | 467,460 |  |              | $ | 465,952 | 
|Oil, natural gas and other mineral properties                                                       |  |              | 2       |  |              |   | 2       | 
|                                                                                                    |  |              |         |  |              |   |         | 
|Total assets                                                                                        |  | $            | 467,462 |  |              | $ | 465,954 | 
|                                                                                                    |  |              |         |  |              |   |         | 
|                                                                                                    |  |             
|Liabilities and Trust Corpus                                                                        |  |              |         |  |              |   |         | 
|                                                                                                    |  |             
|Current liabilities:                                                                                |  |              |         |  |              |   |         | 
|Income distributable to unitholders                                                                 |  | $            | 1,682   |  |              | $ |        | 
|Federal income taxes payable                                                                        |  |              |        |  |              |   | 883     | 
|                                                                                                    |  |              |         |  |              |   |         | 
|Total current liabilities                                                                           |  | $            | 1,682   |  |              | $ | 883     | 
|                                                                                                    |  |              |         |  |              |   |         | 
|                                                                                                    |  |             
|Trust corpus  1,386,525 units of beneficial interest authorized, 1,386,375 issued at nominal
value |  | $            | 465,780 |  |              | $ | 465,071 | 
|                                                                                                    |  |              |         |  |              |   |         | 
|                                                                                                    |  | $            | 467,462 |  |              | $ | 465,954 | 
|                                                                                                    |  |              |         |  |              |   |         | 

TIDELANDS CONSOLIDATED STATEMENTS OF DISTRIBUTABLE INCOME



|                                                 |  |                              |         |   |      |   |         |      |  |   |         | 
|------------------------------------------------ |  | ---------------------------- | ------- | - | ---- | - | ------- | ---- |  | - | ------- | 
|                                                 |  | Twelve Months Ended June 30, |        
|                                                 |  | 2018                         |         |   | 2017 |   |         | 2016 | 
|Income                                           |  | $                            | 128,193 |   |      | $ | 215,434 |      |  | $ | 324,993 | 
|Expenses                                         |  |                              | 128,195 |   |      |   | 132,657 |      |  |   | 129,862 | 
|                                                 |  |                              |         |   |      |   |         |      |  |   |         | 
|Distributable income before Federal income taxes |  |                              | (2      | ) |      |   | 82,777  |      |  |   | 195,131 | 
|Federal income taxes of Tidelands subsidiary    |  |                              |        |   |      |   | 1,133   |      |  |   | 3,019   | 
|                                                 |  |                              |         |   |      |   |         |      |  |   |         | 
|Distributable income                             |  | $                            | (2      | ) |      | $ | 81,644  |      |  | $ | 192,112 | 
|                                                 |  |                              |         |   |      |   |         |      |  |   |         | 



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##### Table of Contents

Tidelands is a reporting company under the Securities Exchange Act of 1934, as amended, and has
filed its Annual Report on Form 10-K for the fiscal year ended December 31, 2017.

(4) Summary of
Quarterly Financial Data (Unaudited)

The following quarterly financial information for fiscal years 2018 and 2017 is unaudited;
however, in the opinion of management, all adjustments necessary for a fair statement of the results of operations for the interim periods have been included.



|                   |  |        |         |  |          |   |         |                     |  |   |                             |  |  |   |      | 
|------------------ |  | ------ | ------- |  | -------- | - | ------- | ------------------- |  | - | --------------------------- |  |  | - | ---- | 
|                   |  | Income |         |  | Expenses |   |         | DistributableIncome |  |   | DistributableIncomePer Unit | 
|Quarter ended:     |  |        |         |  |          |   |         |                     |  |   |                             |  |  |   |      | 
|September 30, 2016 |  | $      | 188,692 |  |          | $ | 17,313  |                     |  | $ | 171,379                     |  |  | $ | 0.09 | 
|December 31, 2016  |  |        | 211,791 |  |          |   | 77,001  |                     |  |   | 134,790                     |  |  |   | 0.07 | 
|March 31, 2017     |  |        | 217,585 |  |          |   | 71,725  |                     |  |   | 145,860                     |  |  |   | 0.07 | 
|June 30, 2017      |  |        | 331,470 |  |          |   | 31,993  |                     |  |   | 299,477                     |  |  |   | 0.15 | 
|                   |  |        |         |  |          |   |         |                     |  |   |                             |  |  |   |      | 
|                   |  | $      | 949,538 |  |          | $ | 198,032 |                     |  | $ | 751,506                     |  |  | $ | 0.38 | 
|                   |  |        |         |  |          |   |         |                     |  |   |                             |  |  |   |      | 
|                   |  |        |         | 
|Quarter ended:     |  |        |         |  |          |   |         |                     |  |   |                             |  |  |   |      | 
|September 30, 2017 |  | $      | 208,879 |  |          | $ | 21,947  |                     |  | $ | 186,932                     |  |  | $ | 0.09 | 
|December 31, 2017  |  |        | 174,590 |  |          |   | 81,528  |                     |  |   | 93,062                      |  |  |   | 0.05 | 
|March 31, 2018     |  |        | 239,859 |  |          |   | 54,606  |                     |  |   | 185,253                     |  |  |   | 0.09 | 
|June 30, 2018      |  |        | 249,314 |  |          |   | 52,642  |                     |  |   | 196,672                     |  |  |   | 0.10 | 
|                   |  |        |         |  |          |   |         |                     |  |   |                             |  |  |   |      | 
|                   |  | $      | 872,642 |  |          | $ | 210,723 |                     |  | $ | 661,919                     |  |  | $ | 0.33 | 
|                   |  |        |         |  |          |   |         |                     |  |   |                             |  |  |   |      | 

(5) Supplemental Information Relating to Oil and Gas Reserves (Unaudited)

Oil and natural gas reserve information relating to Marines and Tidelands royalty interests is not presented because such
information is not available to Marine or Tidelands. Marines share of oil and natural gas sold for its royalty interests and Marines equity in oil and natural gas sold for Tidelands royalty interests were as follows:



|           |  |                              |        |  |      |  |        |      |  |  |        | 
|---------- |  | ---------------------------- | ------ |  | ---- |  | ------ | ---- |  |  | ------ | 
|           |  | Twelve Months Ended June 30, |       
|           |  | 2018                         |        |  | 2017 |  |        | 2016 | 
|Marine:    |  |                              |        |  |      |  |        |      |  |  |        | 
|Oil (bbls) |  |                              | 15,138 |  |      |  | 18,439 |      |  |  | 15,841 | 
|           |  |                              |        |  |      |  |        |      |  |  |        | 
|Gas (mcf)  |  |                              | 20,664 |  |      |  | 40,867 |      |  |  | 56,719 | 
|           |  |                              |        |  |      |  |        |      |  |  |        | 
|Tidelands: |  |                              |        |  |      |  |        |      |  |  |        | 
|Oil (bbls) |  |                              | 1,794  |  |      |  | 3,245  |      |  |  | 5,265  | 
|           |  |                              |        |  |      |  |        |      |  |  |        | 
|Gas (mcf)  |  |                              | 14,203 |  |      |  | 31,982 |      |  |  | 40,549 | 
|           |  |                              |        |  |      |  |        |      |  |  |        | 

(6) Texas Franchise Tax

Texas imposes a franchise tax that applies to most business entities that are formed or qualified to do business, or which are otherwise doing
business, in Texas. Under the Texas franchise tax, a 0.75% tax is imposed for reports due in 2018 on each taxable entitys taxable margin that is apportioned to Texas. Taxable margin is generally defined as revenues less certain costs. Taxable
entities include most entities that provide owners with limited liability protection, including trusts. There are certain exemptions from the franchise tax, including exclusions for certain passive entities that satisfy specified
statutory requirements as described below and entities with total revenues below a specified threshold.



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Under the Texas franchise tax, passive entities include trusts that meet the
following requirements: (a) the trust cannot be a business trust within the meaning of U.S. Treasury Regulation section 301.7701-4(b); (b) at least 90% of the trusts income for the taxable year must
be derived from passive sources (e.g., royalties, bonuses, delay rental income from mineral properties, dividends, interest, and gains from the sale of securities); and (c) no more than 10% of the trusts income for the taxable year can be
derived from an active trade or business (e.g., rent and certain income received by a non-operator under a joint operating agreement pursuant to which the operator is the member of an affiliated group that
includes such non-operator). An entity will determine on an annual basis whether it meets the requirements to be treated as a passive entity for the Texas franchise tax. The Trustee believes that
all or substantially all of the income of the Trust currently is passive, as it consists of royalty income from the sale of oil and natural gas, dividends and interest income. Thus, the Trust anticipates that it will be a passive entity in the tax
year ending in 2018. Subject to any change in the sources of income derived by the Trust or any change in the Indenture, the Trust expects that it will continue to qualify as a passive entity that is not subject to the Texas franchise tax.

If the Trust is exempt from the Texas franchise tax as a passive entity, each unitholder that is subject to the Texas franchise tax as a
taxable entity under the Texas Tax Code should generally include its share of the Trusts revenue in its franchise tax computation. The Texas franchise tax does not apply to natural persons.

In the event the Trust does not qualify as a passive entity, it would not be required to pay any tax and is not considered to owe any Texas
franchise tax for any period in which its annualized total revenue is less than or equal to a certain threshold. For reports due on or after January 1, 2018 and before January 1, 2020, this no tax due threshold is $1,130,000.

Each unitholder is urged to consult its own tax advisor regarding the requirements for filing state tax returns.



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SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to
be signed on its behalf by the undersigned, thereunto duly authorized.



|                         |  |  |  |                                                                                                                                                         |  |                      
|------------------------ |  |  |  | ------------------------------------------------------------------------------------------------------------------------------------------------------- |  | ---------------------
|                         |  |  |  | MARINE PETROLEUM TRUST
(Registrant) 
Simmons Bank, in its capacity as trustee of Marine Petroleum Trust and not in its individual capacity or otherwise
|                         |  |  | 
|Date: September 28, 2018 |  |  |  | By:                                                                                                                                                     |  | /s/ Ron E. Hooper    
|                         |  |  |  |                                                                                                                                                         |  | Ron E. Hooper        
|                         |  |  |  |                                                                                                                                                         |  | Senior Vice President

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the
following persons on behalf of the registrant and in the capacities and on the dates indicated.



|                          |  |  |  |                                                                                                                    |  |                      
|------------------------- |  |  |  | ------------------------------------------------------------------------------------------------------------------ |  | ---------------------
|                          |  |  |  | Simmons Bank, in its capacity as trustee of Marine Petroleum Trust and not in its individual capacity or otherwise
|                          |  |  | 
|Dated: September 28, 2018 |  |  |  | By:                                                                                                                |  | /s/ Ron E. Hooper    
|                          |  |  |  |                                                                                                                    |  | Ron E. Hooper        
|                          |  |  |  |                                                                                                                    |  | Senior Vice President

(The registrant has no directors or executive officers.)