FIFTH AMENDMENT TO
                   BENTHOS, INC. EMPLOYEE STOCK OWNERSHIP PLAN
             AS AMENDED AND RESTATED EFFECTIVE AS OF OCTOBER 1, 1987

         AMENDMENT adopted this 28th day of April, 2000, by Benthos, Inc.
(hereinafter referred to as the "Company"):

                                   WITNESSETH:

         WHEREAS, the Company has heretofore adopted a defined contribution plan
known as the "Benthos, Inc. Employee Stock Ownership Plan", which was amended
and restated effective as of October 1, 1987 (the "Plan"); and

         WHEREAS, the Company, pursuant to Section 16.1 of the Plan, has
reserved the right to amend the Plan at any time by vote of its Board of
Directors; and

         WHEREAS, the Company wishes to amend further the Plan to credit past
service for vesting and eligibility purposes for former employees of Datasonics,
Inc.; and

         WHEREAS, the Company wishes to amend further the Plan to change the
eligibility section and definition of "Year of Service"; and

         NOW, THEREEFORE, effective as of October 1, 1999, unless otherwise
specified, the Plan is hereby amended as follows:

         1. Article III, Section 3.1 is amended by adding the following
            paragraph at the end of the section:

            (d) Each former employee of Datasonics, Inc. who was an Employee on
                October 1, 1999, will be eligible to participate in the Plan as
                long as the Employee has met the eligibility requirements in
                subsection (a).

         2. The definition of "Year of Service" set forth in Article II is
            amended by adding the following paragraph:

            (c) Years of Service shall also include past service with
                Datasonics, Inc., which shall be credited in accordance with
                paragraphs (a) and (b) as though it were service with the
                Company.

         In all other respects the terms of the Plan remain unchanged and are in
full force and effect.



         IN WITNESS WHEREOF, the undersigned Company has caused this Amendment
to be executed by its duly authorized officer as of the day and year set forth
above.

                                            BENTHOS, INC.

                                            By: JOHN L. COUGHLIN
                                               ------------------
                                            Title: President