Exhibit 10.8.4
                           CONFORMED COPY AS DELIVERED
                           ---------------------------

                                                                      Document 1

                              Contract No. MA-13344

                       COMMITMENT TO GUARANTEE OBLIGATIONS

                                       BY

                          THE UNITED STATES OF AMERICA

                                 UNDER TITLE XI

                  OF THE MERCHANT MARINE ACT, 1936, AS AMENDED

                                   ACCEPTED BY

                              TRAILER BRIDGE, INC.
                          Dated as of December 4, 1997


<PAGE> 


                       COMMITMENT TO GUARANTEE OBLIGATIONS

                                       by

                          THE UNITED STATES OF AMERICA

                                   Accepted by

                              TRAILER BRIDGE, INC

                                    Shipowner

                   (Under Title XI, Merchant Marine Act, 1936,
                        as amended, and in effect on the
                       date of this Guarantee Commitment)



                                TABLE OF CONTENTS

    Document
     Number           Document
    --------          --------

          1           Commitment to Guarantee Obligations

                      Schedule One -- Form of Opinion of Counsel

          2           Appendix I -- Form of Bond Purchase Agreement

          3           Appendix II -- Form of Trust Indenture

          4           Schedule A -- Schedule of Definitions to Trust Indenture

          5           Exhibit 1 -- General Provisions Incorporated into the 
                      Trust Indenture by Reference

          6           Exhibit 2 -- Forms of Bond, Guarantee and Trustee's 
                      Authentication Certificate

          7           Exhibit 3 -- Authorization Agreement

          8           Exhibit 4 -- Form of Secretary's Supplemental Indenture

          9           Appendix III -- Security Agreement

         10           Exhibit 1 -- General Provisions Incorporated into the 
                      Security Agreement by Reference

         11           Schedule X -- Schedule of Definitions

         12           Exhibit 2 -- Form of Secretary's Note

         13           Exhibit 3 -- Form of First Preferred Mortgage

         14           Exhibit 4 -- Amended and Restated Title XI Reserve Fund 
                      and Financial Agreement


                                       i
<PAGE>                                 


         15           General Provisions Incorporated into the Title XI Reserve 
                      Fund and Financial Agreement

         16           Exhibit 6 -- Consent of Shipyard

         17           Exhibit 7-- Construction Contract

         18           Exhibit 8-- Depository Agreement

         19           Exhibit 9--- Intercreditor Agreement


                                       ii
<PAGE>                                 


                                                                    Contract No.

                                                                        MA-13344

                       COMMITMENT TO GUARANTEE OBLIGATIONS

                                       by

                          THE UNITED STATES OF AMERICA

                                   accepted by

                              TRAILER BRIDGE, INC.

                                    Shipowner


                               TABLE OF CONTENTS*

                                                                            Page
                                                                            ----

Parties.....................................................................  1

Recitals....................................................................  1

ARTICLE I         Findings and Determinations of Secretary..................  3

ARTICLE II        Commitment to Guarantee Obligations.......................  4

ARTICLE III       The Obligations...........................................  4

ARTICLE IV        Covenants of the Shipowner................................  5

ARTICLE V         Conditions to Execution and Delivery of the Authorization 
                  Agreement and the Security Agreement; Conditions to be 
                  Fulfilled on the Bond Closing Date........................  6

ARTICLE VI        Variation of Guarantee Commitment.........................  9

ARTICLE VII       Termination or Assignment of Guarantee Commitment.........  9

ARTICLE VIII      Conformity To Regulations................................. 10

ARTICLE IX        Miscellaneous............................................. 10

                  Signatures................................................ 12

----------------

    *This Table of Contents is not a part of the Guarantee Commitment and has no
bearing upon the interpretation of any of its terms and provisions.


                                       iii
<PAGE>                                 


Table A

Schedule One to Guarantee Commitment
Appendix I - Form of Bond Purchase Agreement
Appendix II - Form of Trust Indenture
Appendix III - Security Agreement


                                       iv
<PAGE>                                 


                       COMMITMENT TO GUARANTEE OBLIGATIONS

                                       by

                          THE UNITED STATES OF AMERICA

                                   Accepted by

                              TRAILER BRIDGE, INC.

                                    Shipowner


                               -------------------

         THIS COMMITMENT TO GUARANTEE OBLIGATIONS, dated as of December 4, 1997
(the "Guarantee Commitment"), made and entered into by the UNITED STATES OF
AMERICA (the "United States"), represented by the SECRETARY OF TRANSPORTATION,
acting by and through the MARITIME ADMINISTRATOR (the "Secretary"), and accepted
on said date by TRAILER BRIDGE, INC. a Delaware corporation (the "Shipowner").

RECITALS:
--------

         A. The Shipowner is proposed to become the sole owner of the three
408'9" x 100' container deck barges (the "Vessels" when used collectively and
each a "Vessel" when used singularly) to be built pursuant to a certain
construction contract, dated December 30, 1996 (as heretofore or hereafter
amended, including by Amendment No. 1 hereinafter referred to, the "Construction
Contract") originally made with Halter Marine, Inc., a Nevada corporation (the
"Shipyard") by Shipowner's affiliate Coastal Ship, Inc., assigned to Shipowner
and amended pursuant to Amendment No. 1 thereto dated as of October 8, 1997 and
by a certain Intercreditor Agreement dated as of the Closing Date among
Shipowner, the Shipyard, and the Secretary, among others.

         B. To aid in financing the construction of the Vessels, the Shipowner
will borrow an aggregate principal amount approximately equal to, but in no
event in excess of 87 1/2% of the Actual Cost computed as of the Closing Date.

         C. As one means of such financing, the Shipowner has entered into a
bond purchase agreement (the "Bond Purchase Agreement") with the purchaser named
therein providing for the sale and delivery, on the Closing Date, of not in
excess of $16,918,000 aggregate principal amount of bonds designated "United
States Government Guaranteed Ship Financing Bonds, 1997 Series II" (the
"Obligations") having the maturity date and interest rate set forth in the Bond
Purchase Agreement and the Obligations.


                                       1
<PAGE>                                 


         D. The Shipowner will on the Closing Date, execute and deliver an
Indenture (the "Indenture"), between the Shipowner and State Street Bank and
Trust Company, as Indenture Trustee (the "Indenture Trustee"), in connection
with the Obligations to be issued in respect of the Vessels, in the aggregate
amount, with the maturity and bearing interest at the rate specified in the
Trust Indenture.

         E. Under the Authorization Agreement (the "Authorization Agreement"),
Contract MA-13345 to be entered into on the Closing Date between the Secretary
and the Indenture Trustee, the Indenture Trustee will be authorized to endorse
and execute, by means of facsimile signature of the Secretary and the facsimile
seal of the Department of Transportation, on each of the Obligations issued and
to authenticate a guarantee by the Secretary of the payment in full of all the
unpaid interest on, and the unpaid balance of the principal of, each Obligation,
including interest accruing between the date of default under such Obligation
and the date of payment by the Secretary (individually, a "Guarantee" and,
collectively, the "Guarantees").

         F. The Shipowner, as security for the Guarantees, and as security to
the Secretary for the payment to the Secretary of the principal of, and the
interest due or to become due on, the Secretary's Note to be executed in
accordance with the terms thereof, will, on the Closing Date, enter into a
Security Agreement with the Secretary (the "Security Agreement"), Contract
MA-13346, pursuant to which the Shipowner will assign to the Secretary, among
other things, all of the Shipowner's interest in the Construction Contract, and
all other contracts which relate to the construction of the Vessels, as
specified therein, and all property, including the Vessels, in which the
Shipowner has or will have an interest pursuant to the Construction Contract.

         G. The Shipowner will as further security to the Secretary, execute and
deliver on the date of the delivery of the first Vessel to be delivered pursuant
to the Construction Contract, a First Preferred Fleet Mortgage, Contract
MA-13347, created under and pursuant to Chapter 313, Title 46 United States
Code, to the Secretary, as Mortgagee, upon and attaching to such Vessel in the
form of Exhibit 3 to the Security Agreement (or in the case of the second Vessel
and third to be delivered, in the form provided for in Exhibit B to said Exhibit
3).

         H. In connection with the execution and delivery of the Security
Agreement, the Shipyard will enter into a consent to the assignment of the
Construction Contract (the "Consent of Shipyard").

         I. In order to implement certain aspects of the transactions
contemplated by the Security Agreement and the Indenture, the Secretary, the
Shipowner and State Street Bank and Trust Company (the "Depository") will enter
into an Amendment and Restatement of the Depository Agreement, Contract MA-13308
(as so amended and restated, the "Depository Agreement") and the parties thereto
will enter into the Intercreditor Agreement.


                                       2
<PAGE>                                 


         J. The Shipowner will as further security to the Secretary, enter into
an Amendment and Restatement of the Title XI Reserve Fund and Financial
Agreement, Contract MA-13309, with the Secretary (as so amended and restated,
the "Title XI Reserve Fund and Financial Agreement").


                               W I T N E S S ET H:
                               ------------------


         That under the provisions of Title XI of the Merchant Marine Act, 1936,
as amended and in effect on the date hereof (said provisions, as so amended and
in effect on the date hereof, being called "Title XI") and in consideration of
(i) the covenants of the Shipowner contained herein, (ii) the payment by the
Shipowner to the Secretary of the charges for this Guarantee Commitment pursuant
to Section 1104(f) of Title XI and (iii) other good and valuable consideration,
the receipt and sufficiency of which are hereby acknowledged, the Secretary
hereby commits itself as herein provided.

         The forms of following executed documents are annexed to each
counterpart of this Guarantee Commitment: the Security Agreement, the Title XI
Reserve Fund and Financial Agreement, and the Depository Agreement.

         Annexed to each counterpart of this Guarantee Commitment are also the
forms of the Construction Contract, Consent of Shipyard, the Bond Purchase
Agreement, the Indenture, the Bonds, the Authorization Agreement, the Mortgage,
the Intercreditor Agreement, and the Secretary's Note. As used herein, the
"Closing Date" refers to the date for the execution and delivery of the
Obligations as provided in the Bond Purchase Agreement annexed hereto, subject
to the conditions contained in Article V hereof.

         The Consent of Shipyard, the Construction Contract, the Security
Agreement, the Title XI Reserve Fund and Financial Agreement, the Intercreditor
Agreement, the Bond Purchase Agreement, the Indenture, the Bonds, the
Authorization Agreement, the Mortgage, and the Secretary's Note (except as
otherwise required by the Secretary), shall be executed and delivered
substantially in the respective forms annexed hereto, except that the blanks, if
any, therein shall be filled in as contemplated therein and herein and, except
further that the interest rates of the Bonds must be further approved by the
Secretary.

                                    ARTICLE I

                    Findings and Determinations of Secretary

         Pursuant to Section 1104(d) of Title XI, the Secretary has found that
the property or project with respect to which the Obligations will be executed
will be, in his opinion, economically sound.


                                       3
<PAGE>                                 


         Pursuant to Sections 1101(f), 1101(g) and 1104(b)(2) of Title XI, the
Secretary has determined that the aggregate of the Actual Cost of the Vessels is
$19,335,870. The Actual Cost for each Vessel is comprised of the amounts
determined by the Secretary set forth in Table A annexed hereto, and the
Secretary has determined that the amounts set forth in said Table A are itemized
as also set forth therein. The Secretary may make a redetermination of the
Actual Cost of one or more of the Vessels to include, in addition to the items
set forth or referred to in said Table A, any other items or any increase or
decrease in the amounts of the items set forth or referred to therein.

         On the Closing Date, the aggregate principal amount of the Bonds will
not exceed 871/2% of the Actual Cost as of the Closing.

         Pursuant to Section 1104(b)(3) and 1104(b)(5) of Title XI,
respectively, the Secretary has determined that the maturity date of the
Obligations is satisfactory and that the interest rate to be borne by the Bonds
(exclusive of the charges for the Guarantee Fee and service charges, if any) to
be issued on the Closing Date is reasonable, taking into account the range of
interest rates prevailing in the private market for similar loans and risks
assumed by the Secretary.

         Pursuant to Section 1104(b)(4) of Title XI, the Secretary has
determined that payments of principal required by the Obligations are
satisfactory.

                                   ARTICLE II

                       Commitment to Guarantee Obligations

         The United States, represented by the Secretary, HEREBY COMMITS ITSELF
TO GUARANTEE (as provided in the Obligations) the payment of the unpaid interest
on, and the unpaid balance of the principal of, the Obligations, including
interest accruing between the date of default under the Obligations and the
payment in full of the Guarantees, and, to effect this Guarantee Commitment,
hereby commits itself to execute and deliver the Authorization Agreement, the
Security Agreement, the Title XI Reserve Fund and Financial Agreement, and the
Depository Agreement on the Closing Date and to execute the Mortgage on each
Vessel on the date of her respective delivery.


                                       4
<PAGE>                                 


                                   ARTICLE III

                                 The Obligations

     The Obligations shall be as provided in the Indenture and in the form of
the Obligations annexed as Exhibit 2 to the Indenture. The Obligations shall be
subject to all of the terms and conditions set forth in the Indenture and in the
forms thereof. The Indenture, the Bonds, the Secretary's Note, the Mortgage, the
Title XI Reserve Fund and Financial Agreement, and the Depository Agreement
shall be executed and delivered by the Shipowner on (except for the Mortgage,
which the Shipowner covenants to execute upon each Vessel on the respective date
of her delivery) the Closing Date. The forms of the Bond Purchase Agreement, the
Offering Circular, the Indenture, the Obligations, the Authorization Agreement,
the Security Agreement, the Mortgage, the Secretary's Note, the Title XI Reserve
Fund and Financial Agreement, and the Depository Agreement are hereby approved
by the Secretary.


                                   ARTICLE IV

                           Covenants of the Shipowner

         The Shipowner represents and, until termination of this Guarantee
Commitment, agrees:

                  (a) that each Vessel has been or will be constructed
substantially in accordance with the plans and specifications, as applicable,
pursuant to the Construction Contract in a shipyard within the United States
approved by the Secretary and on the respective delivery date of each Vessel,
each Vessel will be documented under the laws of the United States;

                  (b) to furnish to the Secretary, promptly upon written
request, such reasonable, material and pertinent reports, evidence, proof or
information, in addition to that furnished pursuant to the further provisions of
this Guarantee Commitment or in the application for this Guarantee Commitment
under Title XI or otherwise available to the Secretary, as the Secretary may
reasonably deem necessary or appropriate in connection with the performance by
the Secretary of his duties and functions under the Act;

                  (c) to maintain records of all amounts paid or obligated to be
paid by or for the account of the Shipowner for the construction of each Vessel;

                  (d) to permit the Secretary, promptly upon request, to make
such reasonable, material and pertinent examination and audit of the Shipowner's
books, records and accounts and to take such information therefrom and make such
transcripts or copies thereof, as the Secretary may reasonably deem necessary or
appropriate in connection with the performance by the Secretary of his duties
and functions under the Act;

                  (e) to maintain its United States citizenship within the
meaning of Section 2 of the Shipping Act, 1916, as amended, for the purpose of
operation of the Vessels in the trade or trades in which the Shipowner proposes
to operate the Vessels, to the satisfaction of the Secretary and, at the time of
the execution and delivery of the Authorization Agreement, to submit to the
Secretary such supplemental proof of citizenship as the Secretary may deem
appropriate to evidence the continued United States citizenship of the Shipowner
for said purpose; and

                  (f) to execute and deliver the Bond Purchase Agreement, the
Bonds, the Security Agreement, the Indenture, the Secretary's Note, the
Mortgage, the Title XI Reserve Fund and Financial Agreement, the Consent of
Shipyard and the Depository Agreement.


                                       5
<PAGE>                                 


                                    ARTICLE V

                   Conditions to Execution and Delivery of the
               Authorization Agreement and the Security Agreement

         On the Closing Date, the Authorization Agreement shall be executed and
delivered by the United States and the Indenture Trustee; the Security Agreement
and the Title XI Reserve Fund and Financial Agreement shall be executed and
delivered by the Shipowner and the Secretary; the Indenture shall be executed
and delivered by the Shipowner and the Indenture Trustee; the Construction
Contract shall have been executed and delivered by the Shipowner and the
Shipyard; the Consent of the Shipyard shall be executed and delivered by the
Shipyard; the Intercreditor Agreement shall have been executed and delivered by
all parties thereto; the Depository Agreement shall be executed and delivered by
the Shipowner, the Secretary and the Depository; the Secretary's Note shall be
executed and delivered and the Bonds shall be issued and delivered by the
Shipowner; and the Bond Purchase Agreement shall be executed and delivered by
the Shipowner and the purchaser of the Bonds. The obligation of the United
States represented by the Secretary to execute and deliver the Authorization
Agreement, the Security Agreement, the Mortgage, the Depository Agreement and
the Title XI Reserve Fund and Financial Agreement on the Closing Date shall be
subject to the following conditions unless waived in writing by the Secretary:

         (a) the Closing Date shall occur prior to December 31, 1997;

         (b) on the Delivery Date, each Vessel shall be free of any claim, lien,
charge, mortgage or other encumbrance of any character (except the Security
Agreement, and liens otherwise permitted by Section 2.04 of Exhibit 1 to the
Security Agreement); and on the Closing Date the Bond Purchase Agreement shall
have been executed and delivered on or prior to the Closing Date and the
Indenture and the Obligations shall have been duly executed and delivered on the
Closing Date;

         (c) on the Closing Date, the Shipowner shall be a citizen of the United
States within the meaning of Section 2 of the Shipping Act, 1916, as amended,
and shall have furnished to the Secretary an affidavit setting forth data
showing such citizenship to the Secretary's satisfaction at least 20 days prior
to the Closing Date and the Shipowner shall have submitted pro forma affidavits
at least ten days prior to the Closing Date;

         (d) (i) there shall have been delivered to the Secretary two executed
counterparts of the Bond Purchase Agreement, and two executed counterparts of
the Indenture, (ii) two specimen copies of the Obligations issued under the
Indenture; and (iii) two copies of all other documents delivered by the
Shipowner or the Indenture Trustee on the Closing Date;


                                       6
<PAGE>


         (e) the following representations and warranties shall have been made
to the Secretary in writing and shall be true as of the Closing Date:

                  (i) the Shipowner is a corporation duly organized, validly
         existing and in good standing under the laws of the State of Delaware,
         has not failed to qualify to do business in any jurisdiction in the
         United States in which its business or properties require such
         qualification, and had and has full legal right, corporate power and
         authority to own its own properties and assets and conduct its business
         as it is presently conducted;

                  (ii) the Shipowner had and has legal power and authority to
         enter into and carry out the terms of this Guarantee Commitment, the
         Construction Contract, the Bond Purchase Agreement, the Obligations,
         the Indenture, the Security Agreement, the Secretary's Note, the
         Mortgage, the Title XI Reserve Fund and Financial Agreement, the
         Intercreditor Agreement, and the Depository Agreement;

                    (iii) each and all of the documents and instruments referred
         to in clause (ii) hereof have been duly authorized, executed and
         delivered by the Shipowner and constitute, in accordance with their
         respective terms, legal, valid and binding instruments enforceable
         against the Shipowner, except to the extent limited by applicable
         bankruptcy, reorganization, insolvency, moratorium or the similar laws
         of general application relating to or affecting the enforcement of
         creditors rights as from time to time in effect;

                  (iv) the consummation of the transactions contemplated by and
         compliance by the Shipowner of all the terms and provisions of the
         documents and instruments referred to in clause (ii) hereof will not
         violate any provisions of the Certificate of Incorporation or By-laws
         of the Shipowner and will not result in a breach of the terms and
         provisions of, or constitute a default under any other agreement or
         undertaking by the Shipowner or by which the Shipowner is bound or any
         order of any court or administrative agency entered into in any
         proceedings to which the Shipowner is or has been a party;

                  (v) there is no litigation, proceeding or investigation
         pending or, to the best of the Shipowner's knowledge, threatened,
         involving the Shipowner or any of its property which could prevent or
         jeopardize the performance by the Shipowner of the documents and
         instruments referred to in clause (ii) hereof.

         (f) there shall have been delivered to the Secretary a copy of each
document and legal opinion delivered to the Purchasers of the Obligations on the
Closing Date;

         (g) the Secretary shall have received the initial Guarantee Fee payable
under the Security Agreement;

         (h) all charges levied or assessed by the Secretary under Section
1104(f) of Title XI shall have been paid by the Shipowner;


                                       7
<PAGE>


         (i) the Shipowner shall have performed without material breach its
agreements under Article IV hereof, and the further terms, conditions and
provisions of this Guarantee Commitment shall have been complied with in all
material respects;

         (j) there shall not have occurred any event which constitutes (or after
any period of time or any notice, or both, would constitute) a "Default" under
the Security Agreement;

         (k) there shall have been delivered to the Secretary by the Shipowner
an opinion (or opinions) of counsel acceptable to the Secretary, and in form and
substance satisfactory to the Secretary, to the effect that:

                  (i) by the terms of the Security Agreement, the Shipowner has
         granted to the Secretary a fully perfected, first priority security
         interest in each of the assets which constitutes the Security, as
         defined therein;

                  (ii) all filings and recordings required or available to
         perfect the Secretary's first priority security interests in the
         Security, as defined in the Security Agreement, granted by the
         Shipowner in the Security Agreement, and to render such security
         interests valid and enforceable under the laws of the States of
         Mississippi and Florida (including without limitation, all filings of
         financing statements under the UCC) have been duly effected, and no
         periodic refiling or periodic re-recording is required to protect and
         preserve the perfection and first priority of such security interests,
         except as provided by the laws of such State;

                  (iii) under the terms of the Massachusetts UCC, upon the
         moneys and the shares of the money market mutual fund being credited to
         the fund or funds to be established by the Depository-Bailee in
         accordance with the terms of the Depository Agreement, the Secretary's
         security interest in such collateral will be perfected and the
         Secretary's security interest in such collateral will be a first
         priority security interest under the terms of the Massachusetts UCC
         (with respect to the shares of the money market mutual fund comprised
         in the collateral) and under common law (with respect to moneys
         comprised in the collateral);

         (l) there shall have been executed and delivered to the Secretary an
opinion of counsel to the effect stated in the form annexed hereto as Schedule
One;

          (m) the Secretary shall have received a letter agreement from the
Shipowner to provide the Secretary within a reasonable time after the Closing
Date, with seven conformed copies of the Guarantee Commitment and each of the
Appendices and Exhibits thereto executed on or prior to such date;

          (n) on the Closing Date, the qualifying requirements set forth in
Section 15 of the Title XI Reserve Fund and Financial Agreement shall have been
complied with and certified to as required therein;


                                       8
<PAGE>


          (o) at least ten days prior to the Closing Date, there shall have been
delivered to the Secretary, pro forma balance sheets for the Shipowner as of the
Closing Date, certified by an officer of the Shipowner showing, among other
things, all non-Title XI debt of the Shipowner;

         (p) on the Closing Date, the Shipowner shall certify that all non-Title
XI loans to the Shipowner relating to the Vessels have been discharged save only
such as Shipowner expects to pay from the proceeds of the Obligations; and

         (q) at least ten days prior to the Closing Date the Secretary shall
have been furnished evidence that the Vessels have been insured as required by
the Secretary,

                                   ARTICLE VI

                        Variation of Guarantee Commitment

         No variation from the terms and conditions hereof shall be permitted
except pursuant to an amendment executed by the Secretary and accepted by the
Shipowner.

                                   ARTICLE VII

                Termination or Assignment of Guarantee Commitment

     This Guarantee Commitment may terminate and the parties hereto shall have
no further rights or obligations hereunder, upon written notice by the
Secretary, after the earlier of (a) the termination of the obligations of the
United States pursuant to the Shipowner's failure to satisfy one or more
conditions set forth in Article V hereof or (b) the execution and delivery of
the Security Agreement and the Authorization Agreement.

     This Guarantee Commitment may not be assigned by the Shipowner without the
prior written approval of the Secretary and any attempt to do so shall be null
and void ab initio.

                                  ARTICLE VIII

                           Conformity with Regulations

     The Secretary hereby affirms that, with respect to the rights of the
Indenture Trustee and the Holders of the Obligations, this Guarantee Commitment
conforms to its existing regulations governing the issuance of commitments to
guarantee and guarantees under Title XI of the Act and that this Guarantee
Commitment contains a complete list of conditions required for the execution and
delivery of guarantees including the Guarantees.



                                       9
<PAGE>

                                   ARTICLE IX
                                  Miscellaneous

         (a) The table of contents and the titles of the Articles are inserted
as a matter of convenient reference and shall not be construed as a part of this
Guarantee Commitment. This Guarantee Commitment may be executed in any number of
counterparts, each of which shall be an original, but such counterparts shall
together constitute but one and the same instrument.

         (b) For all purposes of this Guarantee Commitment, unless otherwise
expressly provided or unless the context shall otherwise require:

                  (i) The terms "hereof," "herein," "hereby," "hereto,"
"hereunder," "hereinafter" and "herewith" refer to this Guarantee Commitment as
the same may be supplemented or amended as herein provided.

                  (ii) Terms defined in Schedule X of the Security Agreement
annexed hereto or by reference therein to other instruments shall have the
respective meanings stated in Schedule X or such other instruments.

     IN WITNESS WHEREOF, this Commitment to Guarantee Obligations has been
executed by the United States and accepted by the Shipowner, all as of the day
and year first above written.

                                             UNITED STATES OF AMERICA,
                                             SECRETARY OF TRANSPORTATION


                                             BY:  MARITIME ADMINISTRATOR
(SEAL)
                                             BY: /s/ Joel C. Richard  
                                                 -------------------
                                                 Secretary
                                                 Maritime Administration

Attest:
/s/ Larry G. Main            
-----------------
Assistant Secretary
Maritime Administration

                                             ACCEPTED BY:

                                             TRAILER BRIDGE, INC.
                                             as Shipowner


                                             BY: /s/ William G. Gotimer, Jr.
                                                 ---------------------------


                                       10
<PAGE>


                                     TABLE A

         The aggregate Actual Cost of the Vessels Hull No. 289, Hull No. 290, 
and Hull No.291 as of the date hereof as determined by the Secretary (namely, 
(i) the amounts paid by or for the account of the Shipowner as of the date 
hereof for the Construction of the Hull No. 289, Hull No. 290 and Hull No. 291, 
plus (ii) the amount which the Shipowner was on said date obligated under the 
Construction Contract or otherwise to pay from time to time thereafter for the 
Construction of the Hull No. 289, Hull No. 290 and Hull No. 291) is $19,370,872
calculated and itemized as follows:

                                                         Amount*
                                             Amount*    Obligated
                                              Paid      To be Paid      Total
                                             -------    ----------      -----

Contract Price             Hull 289                                    5,980,806
                           Hull 290                                    5.980,806
                           Hull 291                                    5,980,806

Design, Engineering
and Inspection                                             96,000        288,000
                                                         per Vessel
Net Interest During
Construction                                              132,600        397,800
                                                         per Vessel

Title XI Guarantee Fee                                    235,884**      707,652
per Vessel
Total Actual Cost
 Per Vessel                                             6,445,290


Number of Vessels

         3

Total Actual Cost                                                     19,335,870


*     The Secretary has not yet made findings as to the amounts actually paid to
      date by the Shipowner (or hence as to the remaining amounts which the
      Shipowner is obligated to pay in the future).

** Average for the three (3) Vessels.



                                       11
<PAGE>


              SCHEDULE ONE TO COMMITMENT TO GUARANTEE OBLIGATIONS:
                          FORM OF OPINION(S) OF COUNSEL



                                       12
<PAGE>