<PAGE>   1
THE SECURITIES REPRESENTED BY THIS NOTE HAVE BEEN ACQUIRED FOR INVESTMENT IN A
TRANSACTION EXEMPT FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS
AMENDED, PURSUANT TO SECTION 4(2) OF SAID ACT AND NOT WITH A VIEW TO OR IN
CONNECTION WITH THE DISTRIBUTION THEREOF. NEITHER THIS NOTE NOR THE SECURITIES
ISSUED UPON CONVERSION HEREOF MAY BE OFFERED FOR SALE OR SOLD OR OTHERWISE
DISPOSED OF EXCEPT UPON COMPLIANCE WITH SAID ACT AND AS PERMITTED BY THE
PURCHASE AGREEMENT, A COPY OF WHICH IS ON FILE AND MAY BE INSPECTED AT THE
PRINCIPAL OFFICE OF THE COMPANY.

                         MARINE MANAGEMENT SYSTEMS, INC.

                        SENIOR FIVE-YEAR CONVERTIBLE NOTE

                                                                   July 10, 1998

     FOR VALUE RECEIVED, the undersigned, MARINE MANAGEMENT SYSTEMS, INC., a
Delaware corporation (the "Company"), hereby promises to pay to
_________________, (the "Holder") or order, the principal amount of
_______________ ($___________), such amount to be due and payable on March 31,
2003. Interest on the unpaid principal balance from the date hereof shall be
payable semi-annually commencing September 30, 1998 (provided that such first
interest payment date shall be for the period commencing as of the date hereof),
and on each March 31 and September 30 thereafter, at the rate of ten (10%)
percent per annum. For all interest payments through March 31, 2000, the
Company, at its option, may elect to pay the interest hereunder by adding to the
outstanding principal amount of this Note, such interest which has not been paid
in cash (the "Additional Principal Amount"). Interest shall begin to accrue on
such Additional Principal Amount beginning on and including the applicable
interest payment date on which such Additional Principal Amount is added to the
outstanding principal amount of this Note. If the Company has elected to pay any
such interest payment hereunder in Additional Principal Amount (to the extent
permitted), it shall so notify the Holder on or before thirty days prior to the
applicable interest payment date. As used herein, the "principal" amount of this
Note at any time shall include the outstanding principal amount of this Note,
including any Additional Principal Amount outstanding as of such date. The
Company shall have the right to prepay, without penalty or premium, all or a
portion of the principal amount of this Note with accrued interest thereon to
the date of such
<PAGE>   2
prepayment upon thirty (30) days' written notice to the Holder at any time
following March 31, 2001. Any prepayment shall be first applied to interest
thereon accrued through the prepayment date and allocated among the then
outstanding Notes pro rata on the basis of the then unpaid principal amount
(including any Additional Principal Amount) of each of such Notes. No prepayment
may be permitted unless, at the time of such prepayment, there is registered
with the Commission for sale by the Holder, shares of Common Stock of the
Company reflecting full conversion of this Note. The Holder shall be entitled to
convert this Note at any time prior to such Prepayment Date.

     Payments of principal and interest shall be made in lawful money of the
United States of America at the principal office of the Holder or at such other
place as the Holder hereof shall have designated to the Company in writing.

     This Note is made pursuant to a certain Senior Note Purchase Agreement
dated July 10, 1998 (the "Agreement") between the Company and the Holder (and
the other Holders named therein), and the Holder hereof is entitled to the
benefits of the Agreement and may exercise the remedies provided for thereby or
otherwise available in respect thereof, in case of any material breach thereof
by the Company. (This Note and other Notes identical in terms (except for name
and face amount) issued to Holder and to other Holders who are parties to the
Agreement, are hereinafter collectively called the "Notes".) Payments of
principal and interest in respect of the Notes are senior to and prior in right
of payment to all other indebtedness for borrowed money of the Company, provided
that they shall be pari passu with any borrowings by the Company from a
recognized financial institution for working capital in a principal amount not
to exceed $500,000; provided further that such borrowings for working capital
may be secured by the assets of the Company pursuant to a security agreement and
on terms and conditions reasonably acceptable to the Holder (the "Permitted Bank
Line"). In case of an Event of Default, as defined herein, the unpaid balance of
the principal of this Note may be declared and become due and payable in the
manner provided herein.

     This Note is issued subject to the following additional terms and
conditions:

     1. Interest and Payment.

          1.1 The principal amount of this Note outstanding from time to time
     shall bear simple interest at an annual rate of ten percent (10%) (the
     "Note Rate") from the date hereof (provided that interest shall accrue on
     any Additional Principal Amount beginning on and including the applicable
     interest payment date on which such Additional Principal Amount is added to
     the outstanding principal amount of this Note) until payment in full of all
     amounts of principal and interest outstanding under this Note.


                                       -2-
<PAGE>   3
          1.2 In the event of conversion of all or any portion of this Note,
     interest on this Note shall continue to accrue until the applicable
     conversion date.

          1.3 All payments made by the Company on this Note shall be applied
     first to the payment of accrued unpaid interest on this Note and then to
     the reduction of the unpaid principal balance of this Note.

          1.4 If payment of the outstanding principal amount of any Note,
     together with accrued unpaid interest thereon, is not made on the earliest
     to occur of (i) March 31, 2003; and (ii) any date on which any principal
     amount of, or accrued unpaid interest on, any Note is declared to be, or
     becomes, due and payable pursuant to the terms of such Note prior to March
     31, 2003, then interest shall accrue on the outstanding principal amount
     due under this Note and, to the extent permitted by law, on any unpaid
     accrued interest due on this Note from and after such date of default to
     the date of the payment in full of such amounts (including from and after
     the date of the entry of judgment in favor of Holder in an action to
     collect this Note) at an annual rate equal to the maximum rate of interest
     permitted by applicable law (the "Maximum Rate").

          1.5 In the event that a court of competent jurisdiction determines
     that such amounts paid or agreed to be paid by the Company in connection
     with this Note causes the effective interest rate on this Note to exceed
     the Maximum Rate, such interest or other consideration shall automatically
     be reduced to a rate which results in an effective interest rate under this
     Note equal to the Maximum Rate over the term hereof, and, in such event,
     any amounts received by Holder deemed to constitute excessive interest
     shall be applied first to the payment of accrued unpaid interest on this
     Note and then to the reduction of the unpaid principal balance of this
     Note.

          1.6 In the event that the date for the payment of any amount payable
     under this Note falls due on a Saturday, Sunday or public holiday under the
     laws of the State of New York, the time for payment of such amount shall be
     extended to the next succeeding business day and interest shall continue to
     accrue on any principal amount so effected until the payment thereof on
     such extended due date.

     2. Conversion.

          2.1 Any holder of this Note will have the right at its option at any
     time, and from time to time, prior to receipt of payment in full of the
     principal amount of and interest on this Note to convert, subject to the
     terms and provisions hereof, all or a portion of the principal amount of
     this Note and accrued interest thereon, into shares of the Company's Common
     Stock, $.002 par value per share, at the conversion price hereinafter
     provided.

                                       -3-
<PAGE>   4
     Notwithstanding the foregoing, the holder shall not be entitled to convert
     this Note until six months from issue date, except in the event of a
     transaction referred to in Section 5 below, in which case the holder shall
     be entitled to convert this Note at any time after the public announcement
     of such a transaction.

          2.2 To convert this Note, in whole or in part as provided herein at
     the Holder's election, the Holder hereof shall surrender this Note and give
     written notice to the Company of his intention to convert, stating the
     portion of the Note that is to be converted and the name and address of
     each person in whose name a share or shares of stock issuable upon such
     conversion is to be registered and the number of shares to be issued to
     each such person.

          2.3 As promptly as practical after the surrender and giving of notice
     to convert as herein provided, the Company shall (i) pay the Holder the
     amount of accrued and unpaid interest on this Note to the date on which
     such conversion is made either in cash or by means of Additional Principal
     Amount as set forth above; and (ii) deliver or cause to be delivered at its
     office or agency maintained for that purpose to or upon written order of
     the Holder of the Note certificates representing the number of fully paid
     and nonassessable shares of Common Stock of the Company into which said
     Note is converted and, in the event of partial conversion, a new Note in an
     aggregate principal amount equal to the unconverted portion of said Note,
     dated as of the date to which interest has been paid, and if no interest
     has been paid, dated as of the date the Note is converted in part, and in
     all other respects identical to the Note converted.

          2.4 The conversion price for each share of Common Sock issuable
     pursuant to the conversion of the Note shall initially be One Dollar
     ($1.00) per share in lawful money of the United States of America and shall
     be adjusted as provided in Section 4 hereof, and as provided below
     (hereinafter called the "Conversion Price").

     3. Reserved Shares.

          3.1 The Company covenants and agrees that it has reserved and shall at
     all times reserve and keep available out of its authorized but unissued
     Common Stock, solely for the purpose of issuing such shares upon the
     conversion of the Notes (including any Additional Principal Amount in lieu
     of interest), the full number of shares of Common Stock deliverable upon
     the conversion of all Notes outstanding (including any Additional Principal
     Amount in lieu of interest). The Company covenants and agrees that the
     shares of its Common Stock delivered upon conversion of the Notes shall at
     the time of delivery of the certificates for such shares of Common Stock,
     be validly issued and outstanding and fully paid and nonassessable shares
     of Common Stock. The Company further covenants and agrees that it will pay
     when due and payable any and

                                       -4-
<PAGE>   5
     all Federal and state original issue taxes which may be payable in respect
     of the issue of the Notes or any shares of Common Stock upon the conversion
     of Notes. The Company shall not, however, be required to pay any tax which
     may be payable in respect of any transfer involved in the transfer and
     delivery of Notes, any such tax being payable by the Holder of such Notes
     at the time of surrender.

          3.2 Each person in whose name any certificate for shares of Common
     Stock is issuable upon the exercise of this Note shall for all purposes be
     deemed to have become the holder of record of the Common Stock represented
     thereby on, and such certificate shall be dated, the date upon which the
     Note was duly surrendered and notice of conversion was given; provided,
     however, that if the date of such surrender and notice is a date upon which
     the stock transfer books of the Company are closed, such person shall be
     deemed to have become the record holder of such shares on, and such
     certificate shall be dated, the next business day on which the stock
     transfer books of the Company are open.

     4. Adjustments to Conversion Price.

          4.1 In case the Company shall at any time or from time to time after
     the date of issuance of the Notes issue any additional shares of Common
     Stock (or any security convertible into shares of Common Stock or any
     rights or options to purchase shares of Common Stock) for a consideration
     per share less than the Conversion Price in effect immediately prior to the
     issuance of such additional shares, or without consideration, then, and
     thereafter successively upon each such issuance, the Conversion Price in
     effect immediately prior to the issuance of such additional shares shall
     forthwith be reduced to a price determined by dividing:

               (a) An amount equal to the sum of (i) the number of shares of
          Common Stock outstanding immediately prior to such issuance multiplied
          by the then existing Conversion Price, plus (ii) the consideration, if
          any, received by the Company upon such issuance, by

               (b) The total number of shares of Common Stock outstanding
          immediately after the issuance of such additional shares.

          4.2 The Company shall not be required to make any adjustment of the
     Conversion Price in accordance with Section 4.1 if the amount of such
     adjustment shall be less than $.01, but in such case, any adjustment that
     would otherwise be required then to be made shall be carried forward and
     shall be made at the time of and together with the next subsequent
     adjustment of the Conversion Price which, together with all adjustments
     thereof so carried forward, shall amount to not less than $.01.


                                       -5-
<PAGE>   6
          4.3 For the purpose of adjustments under Section 4.1, the following
     provisions shall also be applicable:

               (a) In the case of the issuance of additional shares of Common
          Stock for cash, the consideration received by the Company therefor
          shall be deemed to be the cash proceeds received for such shares
          without deducting any commissions or other expenses paid or incurred
          by the Company for any underwriting of, or otherwise in connection
          with, the issuance of such shares.

               (b) In case of the issuance (otherwise than upon conversion of
          Notes) of additional shares of Common Stock for a consideration other
          than cash or a consideration a part of which shall be other than cash,
          the amount of the consideration shall be determined in good faith by
          the Board of Directors of the Company.

               (c) In the case of the issuance by the Company after the date of
          issuance of the Notes, of any security that is convertible into shares
          of Common Stock or any rights or options to purchase shares of Common
          Stock, (i) the Company shall be deemed to have issued the maximum
          number of shares of Common Stock deliverable upon the exercise of such
          rights or options or upon conversion of such securities and (ii) the
          consideration therefor shall be deemed to be the sum of (x) the
          consideration received by the Company for such convertible securities
          or for such other rights or options as the case may be, without
          deducting therefrom any expenses or commissions incurred or paid by
          the Company for any underwriting or issuance of such convertible
          security or right or option, plus (y) the consideration or adjustment
          payment to be received by the Company in connection with such
          conversion, plus (z) the minimum price at which shares of Common Stock
          are to be delivered upon the exercise of such rights or options, or,
          if no minimum price is specified and such shares are to be delivered
          at the option price related to the market value of the subject shares,
          an option price bearing the same relation to the market value of the
          subject shares at the time such rights or options were granted,
          provided that as to such options such further adjustment as shall be
          necessary on the basis of the actual option price at the time of
          exercise shall be made at such time if the actual option price is less
          than the aforesaid assumed option price.

               (d) For the purpose hereof, any additional shares of Common Stock
          issued as a stock dividend shall be deemed to have been issued for no
          consideration.

               (e) The number of shares of Common Stock at any time outstanding
          shall include (i) all outstanding common stock of the Company, and
          (ii) the aggregate number of shares deliverable in respect of the
          convertible securities, rights and options referred to in this Section
          4, provided that, to the extent that any such options, warrants or
          conversion privileges are not exercised, such shares shall be deemed
          to be outstanding only until the expiration dates of the rights,
          options or conversion privilege

                                       -6-
<PAGE>   7
          or the prior cancellation thereof. Notwithstanding the foregoing,
          there shall not be taken into account, for the purpose of any
          computation made pursuant to Section 4, whether for the determination
          of the number of shares of Common Stock issued or outstanding on or
          prior to any date, or otherwise: (i) any options, warrants, or rights
          to purchase shares of Common Stock of the Company included on Schedule
          2.4 to the Agreement, (ii) options to purchase up to 450,000 shares of
          Common Stock issued pursuant to the Company's Stock Option Plan if the
          exercise price thereof is at least $1.00 per share, or (iii) any
          shares of Common Stock issued upon the exercise of any such options,
          warrants, or conversion rights referenced in the foregoing clauses (i)
          and (ii).

               (f) Notwithstanding the foregoing, upon the expiration or other
          termination of such options, rights or warrants, if any thereof shall
          not have been exercised, the number of shares of Common Stock deemed
          to be issued and outstanding pursuant to subparagraphs (d) and (e)
          shall be reduced by such number of shares of Common Stock as to which
          options, warrants and/or rights shall have expired or terminated
          unexercised, and such number of shares of Common Stock shall no longer
          be deemed to be issued and outstanding, and the Conversion Price then
          in effect shall forthwith be readjusted and thereafter be the price
          which it would have been had adjustment been made on the basis of the
          issuance only of shares of Common Stock actually issued or issuable
          upon the exercise of those options, rights or warrants as to which the
          exercise rights shall have not have expired or terminated unexercised.

          4.4 If at any time or from time to time the Company shall by
     subdivision, consolidation or reclassification of shares, or otherwise,
     change as a whole, the outstanding shares of Common Stock into a different
     number or class of shares, the shares issuable upon conversion of each Note
     and the Conversion Price per share shall be proportionately and
     correspondingly adjusted so as to give the Holder substantially the same
     rights as the Holder would have had if the Holder had converted this Note
     immediately prior to the occurrence of such event.

          4.5 In case the Company shall declare a dividend upon the Common Stock
     payable otherwise than out of earnings or earned surplus and otherwise than
     in Common Stock, the Conversion Price in effect immediately prior to the
     declaration of such dividend shall be reduced by an amount equal, in the
     case of a dividend in cash, to the amount thereof payable per share of the
     Common Stock, or in the case of any other dividend, to the fair value
     thereof per share of the Common Stock as determined, in good faith, by the
     Board of Directors of the Company. For the purposes of the foregoing, a
     dividend other than in cash shall be considered payable out of earnings or
     earned surplus only to the extent that such earnings or earned surplus are
     charged an amount equal to the fair value of such dividend as determined in
     good faith by the Board of Directors of the Company. Such reductions shall
     take

                                       -7-
<PAGE>   8
     effect as of the date as of which the holders of Common Stock of record are
     entitled to such dividend.

          4.6 Irrespective of any adjustments or changes in the Conversion Price
     or the number of shares of Common Stock actually issuable under the several
     Notes, the Notes shall continue to express the Conversion Price per share
     and the number of shares issuable thereunder as expressed in the Notes when
     initially issued.

          4.7 The Company shall give notice to the Holder of any change in the
     Conversion Price under this Note and the method of calculation thereof. The
     Company shall give the Holder advance notice of any cash dividends, rights
     offerings and other transactions directly for the benefit of holders of
     Common Stock of the Company and any transaction referred to in Section 5
     below; provided that in any event such notice shall be provided prior to
     the applicable record date for or the effective date of any such
     transaction.

          4.8 The Company will not, by amendment of its Certificate of
     Incorporation or through any reorganization, transfer of assets,
     consolidation, merger, dissolution, issue or sale of securities or any
     other voluntary action, avoid or seek to avoid the observance or
     performance of any of the terms to be observed or performed hereunder by
     the Company but will at all times in good faith assist in the carrying out
     of all the provisions of this Note and in the taking of all such actions as
     may be necessary or appropriate in order to protect the conversion rights
     of the Holders of the Notes.

     5. Merger.

     If, prior to the payment in full or conversion in full of the Notes, the
Company shall at any time consolidate with or merge into another corporation,
the Holder of each Note will thereafter be entitled to receive, upon the
conversion thereof, the securities or property to which a holder of the number
of shares of Common Stock then issuable upon the conversion of such Note would
have been entitled upon such consolidation or merger, and the Company shall take
such steps in connection with such consolidation or merger as may be necessary
to assure that this Note (or a new Note issued by the succeeding company
containing exactly the same terms as this Note) shall remain in effect and that
the provisions of this Note shall thereafter be applicable, as nearly as
reasonably may be, in relation to any securities or property thereafter issuable
upon the conversion of the Notes. A sale of all or substantially all of the
assets of the Company for a consideration (apart from the assumption of
obligations) consisting principally of securities or, a purchase of 50% or more
of the Common Stock by a person or a group of related people pursuant to a
tender offer or otherwise shall be deemed a consolidation or merger for the
foregoing purposes. In the event of a consolidation

                                       -8-
<PAGE>   9
or merger, provided that the consideration per share of Common Stock to be
received by the Company's shareholders is less than the Conversion Price, the
Holder shall have the option to put the Note to the issuer for the principal
amount of the Note, plus accrued interest; payment to be made at the time of the
closing of any such consolidation or merger. In the event of a consolidation or
merger, provided that the consideration per share of Common Stock to be received
by the stockholders is equal to at least two (2) times the then Conversion
Price, the Company shall have the right to prepay the Note in accordance with
the prepayment provisions set forth above.

     6. Fractional Shares.

     The Company shall not be required to issue certificates representing
fractions of shares of Common Stock upon the conversion of Notes, but in respect
of any final fraction of a share it will make a payment in cash based on the
then market value of the Common Stock as determined by the Company's Board of
Directors.

     7.  Covenants of the Company . The Company  covenants  and agrees that,  so
long as this Note remains outstanding and unpaid, in whole or in part:

          7.1 The Company will not, and will not permit any of its subsidiaries
     to, sell, transfer or in any other manner alienate or dispose of a material
     part of its assets; provided, however, that the Company or any of its
     subsidiaries may effect such a transaction if (i) the transaction is a bona
     fide transaction in which fair market value is received, (ii) no Event of
     Default (defined below) or any condition or event which, with the giving of
     notice or the lapse of time or both, would become an Event of Default has
     occurred or would occur after giving effect to such transaction, and (iii)
     the payment of this Note is duly provided for from such sale proceeds;

          7.2 The Company will not, and will not permit any of its subsidiaries
     to, make any loan to any person who is or becomes a shareholder of the
     Company, other than for reasonable advances for expenses in the ordinary
     course of business;

          7.3 The Company will, and will cause each of its subsidiaries to,
     promptly pay and discharge all lawful taxes, assessments and governmental
     charges or levies imposed upon it, its income and profits, or any of its
     property, before the same shall become in default, as well as all lawful
     claims for labor, materials and supplies which, if unpaid, might become a
     lien or charge upon such properties or any part thereof; provided, however,
     that the Company or such subsidiary shall not be required to pay and
     discharge any such tax, assessment, charge, levy or claim so long as the
     validity thereof shall be contested in good faith by appropriate
     proceedings and the Company or such subsidiary, as the

                                       -9-
<PAGE>   10
     case may be, shall set aside on its books adequate reserves with respect to
     any such tax, assessment, charge, levy or claim so contested;

          7.4 The Company will, and will cause each of its subsidiaries to, do
     or cause to be done all things necessary to preserve and keep in full force
     and effect its corporate existence, rights and franchises and substantially
     comply with all laws applicable to the Company as its counsel may advise;

          7.5 The Company will, and will cause each of its subsidiaries to, at
     all times maintain, preserve, protect and keep its property used or useful
     in the conduct of its business in good repair, working order and condition
     (except for the effects of reasonable wear and tear in the ordinary course
     of business) and will, from time to time, make all necessary and proper
     repairs, renewals, replacements, betterments and improvements thereto;

          7.6 The Company will, and will cause each of its subsidiaries to, keep
     adequately insured, by financially sound reputable insurers, all property
     of a character usually insured by similar corporations and carry such other
     insurance as is usually carried by similar corporations;

          7.7 The Company will, promptly following the occurrence of an Event of
     Default or of any condition or event which, with the giving of notice or
     the lapse of time or both, would constitute an Event of Default, furnish a
     statement of the Company's President or Chief Financial Officer to Holder
     setting forth the details of such Event of Default or condition or event
     and the action which the Company intends to take with respect thereto;

          7.8 The Company will, and will cause each of its subsidiaries to, at
     all times maintain books of account in which all of its financial
     transactions are duly recorded in conformance with generally accepted
     accounting principles; and

          7.9 The Company shall not, and shall not permit any of its
     subsidiaries to: (a) redeem, purchase or otherwise acquire for
     consideration any shares of capital stock or (b) declare or pay dividends
     of any kind with respect to any capital stock of the Company, except for
     dividends due and payable on the outstanding shares of Series A Preferred
     Stock.

          7.10 The Company will not incur, or permit the incurrence of or
     otherwise permit to be outstanding, any indebtedness which (a) is senior in
     right of payment to the Notes, or (b) is pari passu in right of payment to
     the Notes, except that the Permitted Bank Line may be pari passu in right
     of payment to the Notes, or (c) except with the prior written consent of
     the Purchasers, grants to the holder of such indebtedness (or any

                                      -10-
<PAGE>   11
     affiliated entities) any voting rights with respect to matters voted on by
     holders of the Company's Common Stock.

     8. Events of Default.  If any of the  following  events  (each an "Event of
Default") occurs:

          8.1 The dissolution of the Company or any subsidiary of the Company or
     any vote in favor thereof by the board of directors and shareholders of the
     Company or any subsidiary of the Company; or

          8.2 The Company or any of its subsidiaries becomes insolvent, however
     evidenced, or makes an assignment for the benefit of creditors, or files
     with a court of competent jurisdiction an application for appointment of a
     receiver or similar official with respect to it or any substantial part of
     its assets, or the Company or any of its subsidiaries files a petition
     seeking relief under any provision of the Federal Bankruptcy Code or any
     other federal or state statute now or hereafter in effect affording relief
     to debtors, or any such application or petition is filed against the
     Company or any of its subsidiaries, which application or petition is not
     dismissed or withdrawn within sixty (60) days from the date of its filing;
     or

          8.3 The Company fails to pay the principal amount of this Note or any
     of the other Notes as and when the same becomes due and payable or fails to
     pay the interest on, or any other amount payable under, this Note or any of
     the other Notes on or before the 10th day following the date the same
     becomes due and payable; or

          8.4 The  Company  or any of its  subsidiaries  admits in  writing  its
     inability to pay its debts as they mature; or

          8.5 Except for a transaction which complies with Section 5 above, the
     Company or any of its subsidiaries sells all or substantially all of its
     assets or merges or is consolidated with or into another corporation (other
     than, in the case of a subsidiary of the Company, a sale of assets to
     another wholly-owned subsidiary of the Company or the merger or
     consolidation of such subsidiary with or into another wholly-owned
     subsidiary of the Company or into the Company); or

          8.6 A proceeding is commenced to foreclose a security interest or lien
     in any property or assets of the Company or of any subsidiary of the
     Company as a result of a default in the payment or performance of any debt
     (in excess of $75,000 and secured by such property or assets) of the
     Company or of any subsidiary of the Company; or

          8.7 A final judgement for the payment of money in excess of $75,000 is
     entered against the Company or any subsidiary of the Company by a court of
     competent jurisdiction, and such

                                      -11-
<PAGE>   12
     judgment is not discharged (nor the discharge thereof duly provided for) in
     accordance with its terms, nor a stay of execution thereof procured, within
     thirty (30) days after the date such judgement is entered, and, within such
     period (or such longer period during which execution of such judgment is
     effectively stayed), an appeal therefrom has not been prosecuted and the
     execution thereof caused to be stayed during such appeal; or

          8.8 An attachment or garnishment is levied against the assets or
     properties of the Company or any subsidiary of the Company involving an
     amount which in the aggregate exceeds $75,000 and such levy is not vacated,
     bonded or otherwise terminated within thirty (30) days after the date of
     its effectiveness; or

          8.9 The Company defaults in the due observance or performance of any
     covenant, condition or agreement on the part of the Company to be observed
     or performed pursuant to the terms of this Note (other than the default
     specified in Section 8.3 above) and such default continues uncured for a
     period of thirty (30) days; or

          8.10 The Company defaults in the payment (regardless of amount) when
     due of the principal of, interest on, or any other liability on account of,
     any indebtedness of the Company or any of its subsidiaries (other than the
     Notes, or any of them) having an aggregate face or principal amount in
     excess of $75,000, or a default occurs in the performance or observance by
     the Company of any covenant or condition (other than for the payment of
     money) contained in any note or agreement evidencing or pertaining to any
     such indebtedness, which causes the maturity of such indebtedness to be
     accelerated or permits the holder or holders of such indebtedness to
     declare the same to be due prior to the stated maturity thereof;

     then, upon the occurrence of any such Event of Default and at any time
     thereafter, the Holder of this Note shall have the right (at such Holder's
     option) to declare the principal of, accrued unpaid interest on, and all
     other amounts payable under this Note to be forthwith due and payable,
     whereupon all such amounts shall be immediately due and payable to the
     Holder of this Note, without presentment, demand, protest or other notice
     of any kind, all of which are hereby expressly waived; provided, however,
     that in case of the occurrence of an Event of Default under any of Sections
     8.1, 8.2 or 8.4 above, such amounts shall become immediately due and
     payable without any such declaration by the Holder of this Note.

     9. Suits for Enforcement and Remedies. If any one or more Events of Default
shall occur and be continuing, the Holder may proceed to (i) protect and enforce
Holder's rights either by suit in equity or by action at law, or both, whether
for the specific performance of any covenant, condition or agreement contained
in this Note or in any agreement or document referred to herein or in aid of the
exercise of any power granted in this Note

                                      -12-
<PAGE>   13
or in any agreement or document referred to herein, (ii) enforce the payment of
this Note, or (iii) enforce any other legal or equitable right of the Holder of
this Note. No right or remedy herein or in any other agreement or instrument
conferred upon the Holder of this Note is intended to be exclusive of any other
right or remedy, and each and every such right or remedy shall be cumulative and
shall be in addition to every other right and remedy given hereunder or now or
hereafter existing at law or in equity or by statute or otherwise.

     10. Voting Rights.

     (a) So long as any of the principal amount or accrued interest on this Note
is still outstanding, the Holder shall be entitled to vote on all matters voted
on by holders of Common Stock, voting together as a single class with other
shares entitled to vote at all meetings of the stockholders of the Corporation.
With respect to any such vote, the Holder shall be entitled to cast the number
of votes equal to the number of votes which could be cast in such vote by a
holder of the shares of Common Stock into which this Note is convertible on the
record date for such vote. The foregoing voting rights are in addition to the
voting rights that the Holder will obtain in respect of shares of Common Stock
received upon conversion of this Note.

     (b) The Company shall provide the Holder with prior notification of any
meeting of the shareholders (and copies of proxy materials and other information
sent to shareholders). In the event of any taking by the Company of a record of
its shareholders for the purpose of determining shareholders who are entitled to
receive payment of any dividend or other distribution, any right to subscribe
for, purchase or otherwise acquire (including by way of merger, consolidation or
recapitalization) any share of any class or any other securities or property, or
to receive any other right, or for the purpose of determining shareholders who
are entitled to vote in connection with any Company, the Company shall mail a
notice to the Holder, at least thirty (30) days prior to the consummation of the
transaction or event, whichever is earlier), of the date on which any such
action is to be taken for the purpose of such dividend, distribution, right or
other event, and a brief statement regarding the amount and character of such
dividend, distribution, right or other event to the extent known at such time.

     11. Unconditional Obligation; Fees, Waivers, Other.

          11.1 The obligations to make the payments provided for in this Note
     are absolute and unconditional and not subject to any defense, set-off,
     counterclaim, rescission, recoupment or adjustment whatsoever.

          11.2 If, following the occurrence of an Event of Default, Holder shall
     seek to enforce the collection of any amount

                                      -13-
<PAGE>   14
     of principal of and/or interest on this Note, there shall be immediately
     due and payable from the Company, in addition to the then unpaid principal
     of, and accrued unpaid interest on, this Note, all costs and expenses
     incurred by Holder in connection therewith, including, without limitation,
     reasonable attorneys' fees and disbursements.

          11.3 No forbearance, indulgence, delay or failure to exercise any
     right or remedy with respect to this Note shall operate as a waiver or as
     an acquiescence in any default, nor shall any single or partial exercise of
     any right or remedy preclude any other or further exercise thereof or the
     exercise of any other right or remedy.

          11.4 This Note may not be modified or discharged (other than by
     payment) except by a writing duly executed by the Company and Holder.

          11.5 The Company hereby expressly waives demand and presentment for
     payment, notice of nonpayment, notice of dishonor, protest, notice of
     protest, bringing of suit, and diligence in taking any action to collect
     amounts called for hereunder, and shall be directly and primarily liable
     for the payment of all sums owing and to be owing hereon, regardless of and
     without any notice, diligence, act or omission with respect to the
     collection of any amount called for hereunder or in connection with any
     right, lien, interest or property at any and all times which Holder had or
     is existing as security for any amount called for hereunder.

     12. Miscellaneous.

          12.1 The headings of the various paragraphs of this Note are for
     convenience of reference only and shall in no way modify any of the terms
     or provisions of this Note.

          12.2 All notices required or permitted to be given hereunder shall be
     in writing and shall be deemed to have been duly given when personally
     delivered or sent by registered or certified mail (return receipt
     requested, postage prepaid), facsimile transmission or overnight courier to
     the address of the intended recipient as set forth in the preamble to this
     Note or at such other address as the intended recipient shall have
     hereafter given to the other party hereto pursuant to the provisions of
     this Note.

          12.3 This Note and the obligations of the Company and the rights of
     Holder shall be governed by and construed in accordance with the
     substantive laws of the State of New York without giving effect to the
     choice of laws rules thereof.

          12.4 The Company (i) agrees that any legal suit, action or proceeding
     arising out of or relating to this Note shall be instituted exclusively in
     the New York State Supreme Court, County of New York or in the United
     States District Court for the


                                      -14-
<PAGE>   15
     Southern District of New York, (ii) waives any objection which The Company
     may have now or hereafter based upon forum non conveniens or to the venue
     of any such suit, action or proceeding, and (iii) irrevocably consents to
     the jurisdiction of the New York State Supreme Court, County of New York
     and the United States District Court for the Southern District of New York
     in any such suit, action or proceeding. The Company further agrees to
     accept and acknowledge service of any and all process which may be served
     in any such suit, action or proceeding in the New York State Supreme Court,
     County of New York or in the United States District Court for the Southern
     District of New York and agrees that service of process upon the Company,
     mailed by certified mail to the Company's address, will be deemed in every
     respect effective service of process upon the Company, in any suit, action
     or proceeding. FURTHER, BOTH THE COMPANY AND HOLDER HEREBY WAIVE TRIAL BY
     JURY IN ANY ACTION TO ENFORCE THIS NOTE AND IN CONNECTION WITH ANY DEFENSE,
     COUNTERCLAIM OR CROSSCLAIM ASSERTED IN ANY SUCH ACTION.

          12.5 This Note shall bind the Company and its successors and assigns.

               [conditional end of page, signature page to follow]


                                      -15-
<PAGE>   16
     WITNESS the seal of the Company and the signature of its duly authorized
officers.

                                          MARINE MANAGEMENT SYSTEMS, INC.



                                          By: /s/ Michael P. Barney
                                              -------------------------
                                          Name:  M. P. Barney
                                          Title: CEO




                                      -16-