Rescue boats.

(a) Each passenger vessel of 500 tons gross tonnage and over must carry on each side of the vessel at least one rescue boat approved under approval series 160.156 that is equipped as specified in table 199.175 of this part. (b) Each passenger vessel of less than 500 tons gross tonnage must carry at least one rescue boat approved under approval series 160.156 that is equipped as specified in table 199.175 of this part. (c) A lifeboat is accepted as a rescue boat if, in addition to being approved under approval series 160.135, it is also approved under approval series 160.156.