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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
 
                            ------------------------
 
   
                                  FORM 10-K/A
    
   
                                AMENDMENT NO. 1
    
 
     [ X ]  ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
                              EXCHANGE ACT OF 1934
 
                  FOR THE FISCAL YEAR ENDED DECEMBER 31, 1997
 
                                       OR
 
   [   ]  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
                              EXCHANGE ACT OF 1934
 
                       COMMISSION FILE NUMBER     1-12527
 
                             BAYCORP HOLDINGS, LTD.
             (Exact name of registrant as specified in its charter)
 
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<S>                                               <C>
                    DELAWARE                                      02-0488443
         (STATE OR OTHER JURISDICTION OF                       (I.R.S. EMPLOYER
         INCORPORATION OR ORGANIZATION)                       IDENTIFICATION NO.)

 COCHECO FALLS MILLWORKS, 100 MAIN STREET, 
                   SUITE 201
              DOVER, NEW HAMPSHIRE                                03820-3835
    (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)                      (ZIP CODE)
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       REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA CODE: (603) 742-3388
 
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          SECURITIES REGISTERED PURSUANT TO SECTION 12(b) OF THE ACT:
                          COMMON STOCK, $.01 PAR VALUE
                                (TITLE OF CLASS)
 
                            AMERICAN STOCK EXCHANGE
                  (NAME OF EACH EXCHANGE ON WHICH REGISTERED)
 
        SECURITIES REGISTERED PURSUANT TO SECTION 12(g) OF THE ACT: NONE
 
     Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.  Yes  X   No ___
 
     Indicate by check mark if disclosure of delinquent filers to Item 405 of
Regulations S-K is not contained herein, and will not be contained, to the best
of registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K. [  ]
 
     As of March 9, 1998, the approximate aggregate market value of the voting
stock held by non-affiliates of the registrant was $23,152,610 based on the last
reported sale price of the registrant's Common Stock on the American Stock
Exchange as of the close of business on March 9, 1998. There were 8,262,748
shares of Common Stock outstanding as of March 9, 1998.
 
                      DOCUMENTS INCORPORATED BY REFERENCE
 
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                                                                           PART OF FORM 10-K
                          DOCUMENT                                      INTO WHICH INCORPORATED
                          --------                                      -----------------------
<S>                                                                     <C>
Portions of the Registrant's Proxy Statement                            Items 10, 11, 12 & 13
for the 1998 Annual Meeting of Shareholders                             of Part III
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                                    PART IV
 
ITEM 14.  EXHIBITS, FINANCIAL STATEMENT SCHEDULES AND REPORTS ON FORM 8-K.
 
     (a) Documents filed as a part of this Form 10-K:
 
          1. Financial Statements.  The Consolidated Financial Statements listed
     in the Index to Consolidated Financial Statements and Financial Statement
     Schedules are filed as part of this Annual Report on Form 10-K.
 
   
          2. Financial Statement Schedules.  The Financial Statement Schedules
     listed in the Index to Consolidated Financial Statements and Financial
     Statement Schedules are filed as part of this Annual Report on Form 10-K.
    
 
   
          3. Exhibits.  The Exhibits listed in the Exhibit Index immediately
     preceding such Exhibits are filed as part of this Annual Report on Form
     10-K.
    
 
   
     (b) Reports on Form 8-K:
    
 
   
          None.
    
 
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                                   SIGNATURES
 
     Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the registrant has duly caused this report to be signed on
its behalf by the undersigned, thereunto duly authorized.
 
                                          BayCorp Holdings, Ltd.
 
   
April 16, 1998                            By:    /s/ JOHN A. TILLINGHAST
    
                                            ------------------------------------
                                                    John A. Tillinghast
   
                                                         President
    
   
    
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                                 EXHIBIT INDEX
 
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<CAPTION>
EXHIBIT
NUMBER                            DESCRIPTION OF EXHIBIT
-------                           ----------------------
<C>       <C>  <S>
 3.1      --   Certificate of Incorporation of the Registrant.(1)
 3.2      --   By-laws of the Registrant.(1)
10.1      --   Agreement Between Bangor Hydro-Electric Company, Central
               Maine Power Company, Central Vermont Public Service
               Corporation, Fitchburg Gas and Electric Light Company, Maine
               Public Service Company and EUA Power Corporation relating to
               use of certain transmission facilities, dated October 20,
               1986.(2)
10.2      --   Limited Guaranty by Eastern Utilities Associates of
               Decommissioning Costs in favor of Joint Owners of the
               Seabrook Project, dated May 5, 1990.(2)
10.3      --   Composite Agreement for Joint Ownership, Construction and
               Operation of New Hampshire Nuclear Units, as amended, dated
               November 1, 1990.(2)
10.4      --   Seventh Amendment to and Restated Agreement for Seabrook
               Project Disbursing Agent as amended through and including
               the Second Amendment, by and among North Atlantic Energy
               Service Corporation, Great Bay Power Corporation and other
               Seabrook Project owners, dated November 1, 1990.(2)
10.5      --   Seabrook Project Managing Agent Operating Agreement by and
               among the North Atlantic Energy Service Corporation, Great
               Bay Power Corporation and parties to the Joint Ownership
               Agreement, dated June 29, 1992.(2)
10.6      --   Settlement Agreement by and among EUA Power Corporation,
               Eastern Utilities Associates and the Official Bondholders'
               Committee, dated November 18, 1992.(2)
10.7      --   Purchased Power Agreement between UNITIL Power Corporation
               and Great Bay Power Corporation, dated April 26, 1993.(2)
10.8      --   Power Purchase Option Agreement between UNITIL Power
               Corporation and Great Bay Power Corporation, dated April 26,
               1993.(2)
10.9      --   Second Mortgage and Security Agreement between UNITIL Power
               Corporation and Great Bay Power Corporation, dated December
               22, 1993.(2)
10.10     --   Third Mortgage and Security Agreement between UNITIL Power
               Corporation and Great Bay Power Corporation, dated December
               22, 1993.(2)
10.11     --   Registration Rights Agreement between Great Bay Power
               Corporation and the Selling Stockholders, dated April 7,
               1994 (the "Registration Rights Agreement").(2)
10.12     --   Amendment to Registration Rights Agreement between Great Bay
               Power Corporation and the Selling Stockholders, dated
               November 23, 1994.(2)
10.13     --   Stock and Subscription Agreement among Great Bay Power
               Corporation and the Selling Stockholders, dated April 7,
               1994.(2)
10.14     --   Acknowledgment and Amendment to Stock and Subscription
               Agreement, dated November 23, 1994.(2)
10.15     --   Settlement Agreement by and among Great Bay Power
               Corporation, the Official Bondholders' Committee and the
               Selling Stockholders, dated September 9, 1994.(2)
10.16     --   Letter Agreement, dated December 20, 1994, between Great Bay
               Power Corporation and the Selling Stockholders amending
               Registration Rights Agreement, as previously amended on
               November 23, 1994.(2)
10.17     --   Letter Agreement, dated March 29, 1995, between Great Bay
               Power Corporation and the Selling Stockholders amending
               Registration Rights Agreement, as previously amended on
               November 23, 1994 and December 20, 1994.(2)
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<CAPTION>
EXHIBIT
NUMBER                            DESCRIPTION OF EXHIBIT
-------                           ----------------------
<C>       <C>  <S>
10.18     --   Employment Agreement between John A. Tillinghast and Great
               Bay Power Corporation, dated October 8, 1996.(3)(8)
10.19     --   Incentive Stock Option Agreement, dated as of April 24,
               1995, by and between John A. Tillinghast and Great Bay Power
               Corporation.(4)(8)
10.20     --   Employment Agreement between Frank W. Getman Jr. and Great
               Bay Power Corporation, dated August 1, 1995.(5)(8)
10.21     --   Amendment No. 1 to Employment Agreement between Frank W.
               Getman Jr. and Great Bay Power Corporation, dated September
               17, 1996.(3)(8)
10.22     --   Incentive Stock Option Agreement, dated as of August 1,
               1995, by and between Frank W. Getman Jr. and Great Bay Power
               Corporation.(4)(8)
10.23     --   Incentive Stock Option Agreement, dated as of September 17,
               1996, by and between Frank W. Getman Jr. and Great Bay Power
               Corporation.(3)(8)
10.24     --   Services Agreement between PECO Energy Company and Great Bay
               Power Corporation, dated November 3, 1995.(6)(7)
10.25     --   Warrant Purchase Agreement between PECO Energy Company and
               Great Bay Power Corporation, dated November 3, 1995.(5)
10.26     --   1996 Stock Option Plan of the Registrant.(1)(8)
21.1      --   List of Subsidiaries of the Registrant.(9)
23.1      --   Consent of Arthur Andersen LLP.
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(1) Filed as an exhibit to the Company's Registration Statement on Form S-4
    (Registration Statement 333-3362) filed on July 12, 1996 and incorporated
    herein by reference.
 
(2) Filed as an exhibit to the Registration Statement on Form S-1 of Great Bay
    Power Corporation (Registration No. 33-88232) declared effective on April
    17, 1995 and incorporated herein by reference.
 
(3) Filed as an exhibit to the Company's Annual Report on Form 10-K (File No.
    1-12527) on March 26, 1997 and incorporated herein by reference.
 
(4) Filed as an exhibit to the Quarterly Report on Form 10-Q of Great Bay Power
    Corporation for the quarter ended March 31, 1995 (File No. 0-25748) on May
    9, 1995 and incorporated herein by reference.
 
(5) Filed as an exhibit to the Quarterly Report on Form 10-Q of Great Bay Power
    Corporation for the quarter ended June 30, 1995 (File No. 0-25748) on August
    14, 1995 and incorporated herein by reference.
 
(6) Filed as an exhibit to the Quarterly Report on Form 10-Q of Great Bay Power
    Corporation for the quarter ended September 30, 1995 (File No. 0-25748) on
    November 14, 1995 and incorporated herein by reference.
 
(7) Confidential treatment granted as to certain portions.
 
(8) Management contract or compensation plan or arrangement required to be filed
    as an exhibit pursuant to Item 14(c) of Form 10-K.
 
   
(9) Filed as an exhibit to the Company's Annual Report on Form 10-K for the year
    ended December 31, 1997.
    
 
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