46 C.F.R. § 8.555 – Disenrollment.

(a) Voluntary disenrollment. A company may request SIP disenrollment (which includes all of its vessels) or may request disenrollment of a specific vessel from the SIP by writing to the cognizant OCMI. The OCMI will then issue a letter disenrolling the vessel or company. Disenrolled vessels will be inspected in accordance with the requirements of 46 CFR part 2, subpart 2.01 of this chapter.
(b) Company disenrollment. The OCMI may issue a letter disenrolling the company if the company no longer has at least one enrolled vessel or if the company fails to continue to meet the eligibility requirements in § 8.515.
(c) Vessel disenrollment. The OCMI may issue a letter disenrolling a vessel if any one or more of the following occurs:
1. (1) The sale of the vessel.
2. (2) A finalized letter of warning or assessment of a civil penalty for—
  1. (i) Operating outside the scope of the vessel's COI or Stability Letter;
  2. (ii) Not reporting a personnel or material casualty required to be reported under 46 CFR part 4; or
  3. (iii) A material deficiency listed in § 8.515(b)(3).