(a) The regulations in this subchapter apply to the marine engineering details of installations on vessels required to be inspected and certificated under other subchapters in this chapter as described in § 50.01-10.

(b) The regulations in this subchapter are not retroactive in effect, except as provided in § 50.05-5 or § 50.05-10, or if specifically so provided for at the time specific regulations are amended or added.

(c) The requirements in this subchapter revised or added subsequent to July 1, 1969, are applicable to the installations contracted for after the effective dates of such requirements. Normally, materials, items of equipment, or installations in vessels which have been accepted and passed as satisfactory and meeting the applicable requirements in this subchapter then in effect and which are maintained in good and serviceable condition to the satisfaction of the Officer in Charge, Marine Inspection, may be continued in use until replacement is deemed necessary by such officer or as specified in the regulations.

(d) Items of equipment, which are in use on vessels, previously approved by the Commandant but not complying with the latest specification requirements may be continued in use so long as they are maintained in good and serviceable condition to the satisfaction of the Officer in Charge, Marine Inspection, until replacement is deemed necessary by such officer or as specified in the regulations.

(e) Industrial systems and components on mobile offshore drilling units must meet subpart 58.60 of this subchapter.