Just this bit......
121.361 Flights over-water
A holder of an air operator certificate must ensure that each of the certificate holder’s aeroplanes configured for more than 30 passenger seats and operated over-water on flights where life rafts are required by rule 91.525 to be carried, is equipped with sufficient life rafts with buoyancy and overload capacity to accommodate every occupant of the aeroplane in the event of a loss of one raft of the largest rated capacity.