SOLAS III, Reg 31 - Survival Craft and Rescue boats**
31.2 - Rescue Boats
Cargo ships shall carry at least one rescue boat complying with the requirements of section 5.1 of the Code. A lifeboat may be accepted as a rescue boat, provided that it and its launching and recovery arrangements also comply with the requirements for a rescue boat.
“MOB” Boats is not a SOLAS term and not an international term. Frankly, I have never heard it ever other than on gCaptain. Never at sea and never on shore.
I have not been able to find where an FRC is required by regulation over a rescue boat, any guidance from this crew on that would be appreciated I am always looking for opportunities to be smarter.
According to the LSA Code, the only difference between an FRC and a Rescue Boat is capabilities such as size, speed, maneuverability, etc.