Exhibit 12.1

                       CERTIFICATION OF THE PRINCIPAL EXECUTIVE OFFICER
                     PURSUANT TO RULE 13a-14(a) AND 15d-14(a), AS AMENDED

I, Tor Olav Troim, certify that:

1.   I have reviewed  this annual report on Form 20-F of CalPetro  Tankers (IOM)
     Limited;

2.   Based on my  knowledge,  this  annual  report  does not  contain any untrue
     statement of a material fact or omit to state a material fact  necessary to
     make the statements  made, in light of the  circumstances  under which such
     statements  were made, not misleading with respect to the period covered by
     this annual report;

3.   Based on my  knowledge,  the  financial  statements,  and  other  financial
     information included in this annual report,  fairly present in all material
     respects the financial  condition,  results of operations and cash flows of
     the registrant as of, and for, the periods presented in this annual report;

4.   The  registrant's  other  certifying  officer  and  I are  responsible  for
     establishing and maintaining disclosure controls and procedures (as defined
     in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the company and have:

     a)   designed  such  disclosure  controls  and  procedures,  or caused such
          disclosure   controls  and   procedures  to  be  designed   under  our
          supervision,  to ensure  that  material  information  relating  to the
          registrant,  including its consolidated subsidiaries, is made known to
          us by others within those entities,  particularly during the period in
          which this annual report is being prepared;

     b)   evaluated the effectiveness of the company's  disclosure  controls and
          procedures  and  presented  in this report our  conclusions  about the
          effectiveness of the disclosure controls and procedures, as of the end
          of the period covered by this report based on such evaluation; and

     c)   disclosed in this report any change in the company's internal controls
          over financial  reporting  that occurred  during the period covered by
          the annual  report  that has  materially  affected,  or is  reasonably
          likely to  materially  affect,  the company's  internal  controls over
          financial reporting; and

5.   The company's other certifying  officer and I have disclosed,  based on our
     most recent  evaluation of internal controls over financial  reporting,  to
     the company's  auditors and the audit  committee of the company's  board of
     directors (or persons performing the equivalent function):

     a)   all significant  deficiencies and material weaknesses in the design or
          operation of internal  controls  over  financial  reporting  which are
          reasonably likely to adversely affect the company's ability to record,
          process, summarize and report financial information; and

     b)   any fraud, whether or not material,  that involves management or other
          employees who have a  significant  role in the  registrant's  internal
          controls over financial reporting.

Date: June 26, 2007

/s/ Tor Olav Troim
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    Tor Olav Troim
    Principal Executive Officer