Talk about opening a can of worms Hompy...
I think you'll find that RAF SAR crews in big slow yellow Sea Kings are equally well trained in the Maritime environment as they are any other. In fact, I would have thought that the green helicopter experience of the crews, either from their initial training at Shawbury or previous tours on other types would make them capable of landing in just about any spot that allows 10 ft disc clearance!
Now if you are saying its purely a factor of aircraft speed then you may have a point but I would perhaps leave out mention of the professional on board from your statement.
The maritime nature of B Flights role is a factor of location, not training or capability.