JF,
Just a small point...
It needs more complicated ships and even they cannot operate for recovery in some sea states or visibilities. (How may helos fail to get aboard due motion and vis?)
....this is not an issue, all the RN's helos get back on board - I do not recall there ever being a helo lost due to an inability to recover due to sea state or visibility - or for that matter a diversion ashore. The platform only needs to be within limits (viz and pitch/roll) at the moment of touch down.