<PAGE>
 
                                                                         10.17.2
 
                         SECOND AMENDMENT TO CREDIT
                         --------------------------
                                  AGREEMENT
                                  ---------

     THIS SECOND AMENDMENT TO CREDIT AGREEMENT (the "Amendment"), dated as of
                                                     ---------               
September 30, 1998, is entered into by and among WEST MARINE FINANCE COMPANY,
INC., a California corporation (the "Company"), BANK OF AMERICA NATIONAL TRUST
                                     -------                                  
AND SAVINGS ASSOCIATION, as agent for itself and the Banks (the "Agent"), and
                                                                 -----       
the several financial institutions party to the Credit Agreement (collectively,
the "Banks").
     -----   

                                    RECITALS
                                    --------
                                        
     A.  The Company, Banks, and Agent are parties to a Credit Agreement dated
as of November 24, 1997, and amended on April 10, 1998 (collectively, the
"Credit Agreement") pursuant to which the Banks have extended certain credit
-----------------                                                           
facilities to the Company.

     B.  The Company has requested that the Banks agree to certain amendments of
the Credit Agreement.

     C.  The Banks are willing to amend the Credit Agreement, subject to the
terms and conditions of this Amendment.

                                   AGREEMENT
                                   ---------

     NOW, THEREFORE, for valuable consideration, the receipt and adequacy of
which are hereby acknowledged, the parties hereto hereby agree as follows:

     1.  Defined Terms.  Unless otherwise defined herein, capitalized terms used
         -------------                                                          
herein shall have the meanings, if any, assigned to them in the Credit
Agreement.

     2.  Amendments to Credit Agreement.
         ------------------------------ 

          (a)  The definition of "Applicable Offshore Rate Margin" in Section
1.01 of the Credit Agreement is hereby amended to read as follows in its
entirety:

          "Applicable Offshore Rate Margin" means
           -------------------------------       

               (i)    on the Closing Date and until the earlier of (A) the date
          clause (ii) below becomes applicable, or (B) September 1, 1998, .55%;

               (ii)   on and after the date the Parent receives a rating on the
          Parent or on the Parent's senior long term unsecured debt of "BBB-" or
          better from S&P or "Baa3" or better from Moody's, and so long as the
          Parent's senior long term unsecured debt continues to be rated by
          either S&P or Moody's and such rating does not fall below "BBB-",

                                      -1-
<PAGE>
 
          in the case of S&P, or "Baa3", in the case of Moody's, .40%; and

               (iii)  at all times that neither clause (i) nor clause (ii) is
          applicable, the percentage determined as set forth below:

                    (A) on and after the fifteenth day following receipt by
               Banks and Agent of the financial statements required under
               Section 7.01(a) and (b), which financial statements reflect a
               Fixed Charge Coverage Ratio which is higher than 2.70:1 for the
               most recently concluded fiscal quarter, .45%;

                    (B) on and after the fifteenth day following receipt by
               Banks and Agent of the financial statements required under
               Section 7.01(a) and (b), which financial statements reflect a
               Fixed Charge Coverage Ratio which is higher than 2.35:1, but not
               higher than 2.70:1, for the most recently concluded fiscal
               quarter, .55%;

                    (C) on and after the fifteenth day following receipt by
               Banks and Agent of the financial statements required under
               Section 7.01(a) and (b), which financial statements reflect a
               Fixed Charge Coverage Ratio which is higher than 2.10:1, but not
               higher than 2.35:1, for the most recently concluded fiscal
               quarter, .75%;

                    (D) on and after the fifteenth day following receipt by
               Banks and Agent of the financial statements required under
               Section 7.01(a) and (b), which financial statements reflect a
               Fixed Charge Coverage Ratio which is higher than 1.90:1, but not
               higher than 2.10:1, for the most recently concluded fiscal
               quarter, .875%;

                    (E) on and after the fifteenth day following receipt by
               Banks and Agent of the financial statements required under
               Section 7.01(a) and (b), which financial statements reflect a
               Fixed Charge Coverage Ratio which is 1.90:1 or lower for the most
               recently concluded fiscal quarter, 1.25%;

                    (F) on and after the fifteenth day following the Company's
               failure to deliver to Banks and Agent the financial statements
               required under Section 7.01(a) and (b) within the time periods
               set forth therein, and until the fifteenth day following receipt
               by Bank and Agent of such financial statements (at

                                      -2-
<PAGE>
 
               which time subpart (A) (B), (C), (D) or (E) above shall become
               applicable), 1.25%.

          (b)  The definition of "Commercial Letter of Credit Fee" in Section
1.01 of the Credit Agreement is hereby amended to read as follows in its
entirety :

          "Commercial Letter of Credit Fee" means
           -------------------------------       

               (i)  on and after the date the Parent receives a rating on the
          Parent or on the Parent's senior long term unsecured debt of "BBB-" or
          better from S&P or "Baa3" or better from Moody's, and so long as the
          Company's senior long term unsecured debt continues to be rated by
          either S&P or Moody's and such rating does not fall below "BBB-", in
          the case of S&P, or "Baa3", in the case of Moody's, .125%; and

               (ii) at all times that clause (i) is not applicable, commencing
          on the fifteenth day following the day the Company is first required
          to deliver financial statements to Banks and Agent under Section
          7.01(a) or (b), the percentage determined as set forth below:

                    (A) on and after the fifteenth day following receipt by
               Banks and Agent of the financial statements required under
               Section 7.01(a) and (b), which financial statements reflect a
               Fixed Charge Coverage Ratio which is higher than 2.70:1 for the
               most recently concluded fiscal quarter, .15%;

                    (B) on and after the fifteenth day following receipt by
               Banks and Agent of the financial statements required under
               Section 7.01(a) and (b), which financial statements reflect a
               Fixed Charge Coverage Ratio which is higher than 2.35:1, but not
               higher than 2.70:1, for the most recently concluded fiscal
               quarter, .1875%;

                    (C) on and after the fifteenth day following receipt by
               Banks and Agent of the financial statements required under
               Section 7.01(a) and (b), which financial statements reflect a
               Fixed Charge Coverage Ratio which is higher than 2.10:1, but not
               higher than 2.35:1, for the most recently concluded fiscal
               quarter, .20%;

                    (D) on and after the fifteenth day following receipt by
               Banks and Agent of the financial statements required under
               Section 7.01(a) and (b), which financial statements reflect a
               Fixed Charge Coverage Ratio which is higher than 1.90:1, but not
               higher than

                                      -3-
<PAGE>
 
               2.10:1, for the most recently concluded fiscal quarter, .25%;

                    (E) on and after the fifteenth day following receipt by
               Banks and Agent of the financial statements required under
               Section 7.01(a) and (b), which financial statements reflect a
               Fixed Charge Coverage Ratio which is 1.90:1 or lower for the most
               recently concluded fiscal quarter, .35%;

                    (F) on and after the fifteenth day following the Company's
               failure to deliver to Banks and Agent the financial statements
               required under Section 7.01(a) and (b) within the time periods
               set forth therein, and until the fifteenth day following receipt
               by Bank and Agent of such financial statements (at which time
               subpart (A) (B), (C), (D), or (E) above shall become applicable),
               .35%.

          (c)  The definition of "Standby Letter of Credit Fee" in Section 1.01
of the Credit Agreement is hereby amended to read as follows in its entirety:

          "Standby Letter of Credit Fee" means
           ----------------------------       

               (i)  on and after the date the Parent receives a rating on the
          Parent or on the Parent's senior long term unsecured debt of "BBB-" or
          better from S&P or "Baa3" or better from Moody's, and so long as the
          Company's senior long term unsecured debt continues to be rated by
          either S&P or Moody's and such rating does not fall below "BBB-", in
          the case of S&P, or "Baa3", in the case of Moody's, .40%; and

               (ii) at all times that clause (i) is not applicable, commencing
          on the fifteenth day following the day the Company is first required
          to deliver financial statements to Banks and Agent under Section
          7.01(a) or (b), the percentage determined as set forth below:

                    (A) on and after the fifteenth day following receipt by
               Banks and Agent of the financial statements required under
               Section 7.01(a) and (b), which financial statements reflect a
               Fixed Charge Coverage Ratio which is higher than 2.70:1 for the
               most recently concluded fiscal quarter, .45;

                    (B) on and after the fifteenth day following receipt by
               Banks and Agent of the financial statements required under
               Section 7.01(a) and (b), which financial statements reflect a
               Fixed Charge Coverage Ratio which is higher than 2.35:1, but not
               higher than

                                      -4-
<PAGE>
 
               2.70:1, for the most recently concluded fiscal quarter, .55%;

                    (C) on and after the fifteenth day following receipt by
               Banks and Agent of the financial statements required under
               Section 7.01(a) and (b), which financial statements reflect a
               Fixed Charge Coverage Ratio which is higher than 2.10:1, but not
               higher than 2.35:1, for the most recently concluded fiscal
               quarter, .75%;

                    (D) on and after the fifteenth day following receipt by
               Banks and Agent of the financial statements required under
               Section 7.01(a) and (b), which financial statements reflect a
               Fixed Charge Coverage Ratio which is higher than 1.90:1, but not
               higher than 2.10:1 for the most recently concluded fiscal
               quarter, .875%;

                    (E) on and after the fifteenth day following receipt by
               Banks and Agent of the financial statements required under
               Section 7.01(a) and (b), which financial statements reflect a
               Fixed Charge Coverage Ratio which is 1.90:1 or lower for the most
               recently concluded fiscal quarter, 1.25%;

                    (F) on and after the fifteenth day following the Company's
               failure to deliver to Banks and Agent the financial statements
               required under Section 7.01(a) and (b) within the time periods
               set forth therein, and until the fifteenth day following receipt
               by Bank and Agent of such financial statements (at which time
               subpart (A) (B), (C), (D), or (E) above shall become applicable),
               1.25%.

          (d)  Section 2.10(b) is amended by substituting ".35%" for ".25%" in
the second sentence thereof, by deleting the word "or" at the end of subpart (B)
of clause (ii) thereof, by adding the word "or" to the end of subpart (C) of
clause (ii) thereof, and by adding a new subpart (D) immediately following
subpart (C) of clause (ii) thereof, reading as follows:

                    (D) greater than 1.90:1, but not exceeding 2.10:1, in
               which case the commitment fee shall be calculated at the rate
               of .25% per annum;

          (e)  The first sentence of Section 7.13(b) is amended to read as
follows in its entirety:

               (b)  achieve a Fixed Charge Coverage Ratio of at least the ratio
          indicated below as of the end of each fiscal quarter set forth below:

                                      -5-
<PAGE>
 
<TABLE>
<CAPTION>
 
               Fiscal Quarters                Ratio
               ---------------                -----
               <S>                           <C>
               3rd Qtr 1997 - 2nd Qtr 1998    1.90 to 1.0
 
               3rd Qtr 1998                   1.75 to 1.0
 
               4th Qtr 1998                   1.70 to 1.0
 
               1st Qtr 1999 and thereafter    2.00 to 1.0
</TABLE>

     3.  Representations and Warranties.  The Company hereby represents and
         ------------------------------                                    
warrants to the Agent and the Banks as follows:

          (a)  No Event of Default has occurred and is continuing.

          (b)  The execution, delivery and performance by the Company of this
Amendment have been duly authorized by all necessary corporate and other action
and do not and will not require any registration with, consent or approval of,
notice to or action by, any Person (including any Governmental Authority) in
order to be effective and enforceable.  The Credit Agreement as amended by this
Amendment constitutes the legal, valid and binding obligations of the Company,
enforceable against it in accordance with its respective terms, except as
enforceability may be limited by applicable bankruptcy, insolvency, or similar
laws affecting the enforcement of creditors' rights generally or by equitable
principles relating to enforceability, without defense, counterclaim or offset.

          (c)  All representations and warranties of the Company contained in
the Credit Agreement are true and correct on and as of the date hereof, except
to the extent such representations and warranties expressly refer to an earlier
date, in which case they are true and correct as of such earlier date.

          (d)  The Company is entering into this Amendment on the basis of its
own investigation and for its own reasons, without reliance upon the Agent and
the Banks or any other Person.

     4.  Effective Date.  This Amendment will become effective as of September
         --------------                                                       
30, 1998 (the "Effective Date"), provided that each of the following conditions
               --------------    --------                                      
precedent is satisfied:

          (a)  The Agent has received from the Company and each of Banks a duly
executed original (or, if elected by the Agent, an executed facsimile copy) of
this Amendment, together with a duly executed Guarantor Acknowledgment and
Consent in the form attached hereto.

          (b)  The Agent has received from the Company for the ratable benefit
of the Banks the amount of Fifteen Thousand Dollars ($15,000), representing
payment in full of a non-refundable amendment

                                      -6-
<PAGE>
 
fee, which amount the Company hereby covenants to pay to the Agent for the
benefit of the Banks on demand.

     5.  Reservation of Rights.  The Company acknowledges and agrees that the
         ---------------------                                               
execution and delivery by the Agent and the Banks of this Amendment shall not be
deemed to create a course of dealing or otherwise obligate the Agent or the
Banks to enter into amendments under the same, similar, or any other
circumstances in the future.

     6.  Miscellaneous.
         ------------- 

          (a)  Except as herein expressly amended, all terms, covenants and
provisions of the Credit Agreement are and shall remain in full force and effect
and all references therein and in the other Loan Documents to such Credit
Agreement shall henceforth refer to the Credit Agreement as amended by this
Amendment.  This Amendment shall be deemed incorporated into, and a part of, the
Credit Agreement.  This Amendment is a Loan Document.

          (b)  This Amendment shall be binding upon and inure to the benefit of
the parties hereto and to the Credit Agreement and their respective successors
and assigns.  No third party beneficiaries are intended in connection with this
Amendment.

          (c)  This Amendment shall be governed by and construed in accordance
with the law of the State of California.

          (d)  This Amendment may be executed in any number of counterparts,
each of which shall be deemed an original, but all such counterparts together
shall constitute but one and the same instrument.  Each of the parties hereto
understands and agrees that this document (and any other document required
herein) may be delivered by any party thereto either in the form of an executed
original or an executed original sent by facsimile transmission to be followed
promptly by mailing of a hard copy original, and that receipt by the Agent of a
facsimile transmitted document purportedly bearing the signature of a Bank or
the Company shall bind such Bank or the Company, respectively, with the same
force and effect as the delivery of a hard copy original.  Any failure by the
Agent to receive the hard copy executed original of such document shall not
diminish the binding effect of receipt of the facsimile transmitted executed
original of such document of the party whose hard copy page was not received by
the Agent, and the Agent is hereby authorized to make sufficient photocopies
thereof to assemble complete counterparty documents.

          (e)  This Amendment, together with the Credit Agreement, contains the
entire and exclusive agreement of the parties hereto with reference to the
matters discussed herein and therein.  This Amendment supersedes all prior
drafts and communications with respect thereto.  This Amendment may not be
amended except in accordance with the provisions of Section 11.01 of the Credit
Agreement.

                                      -7-
<PAGE>
 
          (f)  If any term or provision of this Amendment shall be deemed
prohibited by or invalid under any applicable law, such provision shall be
invalidated without affecting the remaining provisions of this Amendment or the
Credit Agreement, respectively.

          (g)  The Company covenants to pay to or reimburse the Agent, upon
demand, for all reasonable costs and expenses (including reasonable Attorney
Costs) incurred in connection with the development, preparation, negotiation,
execution and delivery of this Amendment.

     IN WITNESS WHEREOF, the parties hereto have executed and delivered this
Amendment as of the date first above written.


                                    WEST MARINE FINANCE COMPANY, INC.
                                       
                                    By
                                      ______________________________
                                      John C. Zott
                                      Senior Vice President,
                                      Finance; Chief Financial
                                      Officer; Secretary; and
                                      Treasurer


                                    BANK OF AMERICA NATIONAL TRUST AND SAVINGS
                                    ASSOCIATION, as Agent

                                    By
                                      ______________________________
                                      Gary Flieger
                                      Vice President


                                    BANK OF AMERICA NATIONAL TRUST AND SAVINGS
                                    ASSOCIATION, as a Bank and an Issuing Bank

                                    By
                                      ______________________________
                                      Kenneth E. Jones
                                      Vice President

                                      -8-
<PAGE>
 
                                    NATIONSBANK OF TEXAS, NATIONAL ASSOCIATION,
                                    as a Bank and an Issuing Bank

                                    By
                                      ______________________________
                                      William B. Guffey
                                      Managing Director


                                    FLEET NATIONAL BANK, as a Bank and an
                                    Issuing Bank

                                    By
                                      ______________________________
                                      Jeff Kinney
                                      Vice President

                                      -9-
<PAGE>
 
                      GUARANTOR ACKNOWLEDGMENT AND CONSENT
                      ------------------------------------
                                        
     Each of the undersigned Guarantors hereby (i) acknowledges and consents to
the terms of and the execution, delivery and performance of the foregoing Second
Amendment to Credit Agreement (the "Amendment") (without implying the need for
                                    ---------                                 
any such acknowledgement or consent), and (ii) represents and warrants to the
Agent and the Banks that, both before and after giving effect to the Amendment,
its respective Guaranty remains in full force and effect as an enforceable
obligation of the Guarantor, except as enforceability may be limited by
applicable bankruptcy, insolvency, or similar laws affecting the enforceability
of creditors' rights generally or by equitable principles relating to
enforceability, without defense, counterclaim or offset, and that it is in
compliance with all of its covenants contained therein.  Each Guarantor further
represents that the execution, delivery and performance by such Person of this
Acknowledgement and Consent have been duly authorized by all necessary
corporate, partnership and other action and do not and will not require any
registration with, consent or approval of, notice to or action by, any Person
(including any Governmental Authority) in order to be effective and enforceable.
Each Guarantor remakes as of the Effective Date (as defined in the Amendment)
all of the representations and warranties made by it pursuant to its respective
Guaranty.  Capitalized terms used herein and not otherwise defined have the
respective meanings defined in the Credit Agreement (as defined in the
Amendment).

     IN WITNESS WHEREOF, each of the undersigned has executed this
Acknowledgement and Consent by its duly authorized officers as of this ______
day of ________________, 1998.

                             WEST MARINE, INC., a
                             Delaware corporation

                             By
                               ____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer


                             WEST MARINE PRODUCTS, INC., a
                             California corporation

                             By
                               ____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer

                                      -10-
<PAGE>
 
                             E&B MARINE INC., a 
                             Delaware corporation

                             By
                               ____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer

                                      -11-
<PAGE>
 
                             E&B MARINE SUPPLY, INC., a
                             Maryland corporation

                             By____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer


                             E&B MARINE SUPPLY, INC., a
                             New Jersey corporation

                             By____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer


                             E&B MARINE SUPPLY (Florida), Inc., a
                             Delaware corporation

                             By____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer

                             GOLDBERGS' MARINE DISTRIBUTORS, INC., a 
                             Delaware corporation

                             By____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer

                             JAMES BLISS & CO., INC., a 
                             Massachusetts corporation

                             By____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer

                                      -12-
<PAGE>
 
                             SEA RANGER MARINE INC., a
                             Delaware corporation

                             By____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer


                             KRISTA CORPORATION, a
                             Delaware corporation

                             By____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer


                             CENTRAL MARINE SUPPLY, INC., a 
                             New Jersey corporation

                             By____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer


                             WEST MARINE LBC, INC., a 
                             California corporation

                             By____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer

                                      -13-
<PAGE>
 
                             WEST MARINE IHC I, INC., a 
                             California corporation

                             By____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer


                             WEST MARINE IHC II, INC., a 
                             California corporation

                             By____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer

                             E&B MARINE LBC, INC., a 
                             California corporation

                             By____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer


                             E&B MARINE IHC I, INC., a 
                             California corporation

                             By____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer


                             E&B MARINE IHC II, INC., a
                             California corporation

                             By____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer

                                      -14-
<PAGE>
 
                             W MARINE MANAGEMENT COMPANY, INC., a
                             California corporation

                             By____________________________
                               John C. Zott
                               Senior Vice President,
                               Finance; Chief Financial
                               Officer; Secretary; and
                               Treasurer

                                      -15-