EXHIBIT 5.7

January_________, 2005

Ultrapetrol (Bahamas) Limited
c/o H&J Corporate Services Ltd.
Shirlaw House
87 Shirley Street
P.O. Box SS-19084
Nassau, Bahamas

               Re:  9% First Preferred Ship Mortgage Notes due 2014

Ladies and Gentlemen:

      We have acted as special Panamanian counsel to Ultrapetrol (Bahamas)
Limited, a Bahamas company (the "Company") and to the Company's Panamanian
subsidiaries listed on Exhibit A hereto (each a "Guarantor" and collectively the
"Guarantors" and, together with the Company, the "Ultrapetrol Group") in
connection with the Company's Registration Statement on Form F-4 (the
"Registration Statement") as filed with the United States Securities and
Exchange Commission (the "Commission"), with respect to the Company's offer to
exchange (the "Exchange Offer") up to $180,000,000 of the Company's 9% First
Preferred Ship Mortgage Notes due 2014 (the "Exchange Notes") for an identical
principal amount at maturity of its outstanding 9% First Preferred Ship Mortgage
Notes due 2014 (the "Outstanding Notes"). The Exchange Notes are to be issued
pursuant to the Indenture dated as of November 24, 2004 between the Company, the
Guarantors and Manufacturers Traders and Trust Company, as Trustee (the
"Trustee") (the "Indenture") and, when issued, will be guaranteed by the
Guarantors (the "Guarantees") pursuant to the Indenture. Capitalized terms not
defined herein have the meanings ascribed to them in the Registration Statement.

      We have examined originals or copies, certified or otherwise identified to
our satisfaction, of: (i) the Registration Statement; (ii) the prospectus of the
Company (the "Prospectus") included in the Registration Statement; (iii) the
Indenture; (iv) the form of the Outstanding Notes; (v) the form of the Exchange
Notes and (vi) such corporate documents and records of the Company and the
Guarantors and such other instruments, certificates and documents as we have
deemed necessary or appropriate as a basis for the opinions hereinafter
expressed. In such examinations, we have assumed the authenticity of all
documents submitted to us as originals, the conformity to original documents of
all documents submitted to us as copies or drafts of documents to be executed,
the genuineness of all signatures and the legal competence or capacity of
persons or entities (whoever are or will become signatories thereto) to



Ultrapetrol (Bahamas) Limited
January________, 2005
Page 2

complete the execution of documents. As to various questions of fact that are
material to the opinion hereinafter expressed, we have relied upon statements or
certificates of public officials, directors or officers of the Company and the
Guarantors and others.

      We have further assumed for the purposes of this opinion that each of the
Indenture and all documents contemplated by the Indenture to be executed in
connection with the issuance of the Exchange Notes and Guarantees have been duly
authorized and validly executed and delivered by each of the parties thereto
other than the Company and the Guarantors.

      Based upon and subject to the foregoing, and having regard to such other
legal considerations, which we deem relevant, we are of the opinion that the
Exchange Notes and Guarantees have been duly authorized, executed and delivered
by the Company and the Guarantors.

      We hereby confirm that the discussion under the headings "Enforceability
of Civil Liabilities," "Summary of the Terms of the Exchange Notes: Additional
Amounts," and "Tax Considerations - Panama Tax Considerations" contained in the
Company's Registration Statement on Form F-4, insofar as such discussion
represents legal conclusions or statements of Panamanian law, subject to the
limitations and conditions set forth therein, constitutes the opinion of Tapia,
Linares y Alfaro. It is our further opinion that the discussion set forth under
such captions accurately states our views as to the matters discussed therein.

      This opinion is limited to the laws of Panama. This opinion is rendered as
of the date hereof, and we have no responsibility to update this opinion for
events or circumstances occurring after the date hereof, nor do we have any
responsibility to advise you of any change in the laws after the date hereof.

      We hereby consent to the filing of this opinion as an exhibit to the
Company's Registration Statement on Form F-4 to be filed with the United States
Securities and Exchange Commission with respect to the Exchange Notes, without
admitting we are "experts" within the meaning of the Securities Act of 1933, as
amended, or the rules and regulations of the Commission thereunder with respect
to any part of the Registration Statement.

Very truly yours,

Tapia, Linares y Alfaro

Mario E. Correa



Ultrapetrol (Bahamas) Limited
January__, 2005
Page 3

                                    EXHIBIT A

Baldwin Maritime Inc.
Bayham Investments S.A.
Cavalier Shipping Inc.
Danube Maritime Inc.
Imperial Maritime Ltd. (Bahamas) Inc.
Kattegat Shipping Inc.
Oceanview Maritime Inc.
Parkwood Commercial Corp.
Princely International Finance Corp.
Regal International Investments S.A.
Riverview Commercial Corp.
Stanmore Shipping Inc.
Tipton Marine Inc.
Ultrapetrol International S.A.