I commanded two Coast Guard Cutters with flight decks and can say I'm a bit familiar with CG flight operations at sea, from the ship perspective. Most of what has been mentioned here is accurate. There ARE also a few cruise ships with REAL 'helo pads' but for far as the USCG, you won;t see many landings ... there are ALWAYS exceptions ... but in general, the pilots I worked with would avoid this .... doing a hoist is almost always safer than landing on an unfamiliar moving target.
- as mentioned the military vessels that land helos (or fixed wing airplanes) practice this ALOT. Standard procedure is KEY ... in signals, communications and most importantly what will happen if something goes wrong. I've NEVER seen the CG practice landings with a cruise ship .... we practice a lot, and have a standardization inspection regularly .... everything is inspected from procedure to equipment and even the paint on the flight deck (condition of the "non skid" coating, and measuring the flight deck markings to insure they are correct to within less than an inch)
- a helo sitting on the deck of a ship with the blades spinning is an unstable object. Tying down the helo quickly is important ... this is something that is practiced practiced practiced on CG Cutters .... ditto the never seen practice comment above
- when a (CG) helo lands ... there are a million things that can go 'wrong' and ground the helo until the thing gets fixed. Cutters carry mechanics and parts .... what we really don't want is to have a helo land on a cruise ship THEN get a warning light! If the same warning light comes on during a hoist aka 'in flight', 99 times of 100 the procedure is abort mission & (try to) fly home
This applies to USCG helos only of course but that is about the only helo you're likely to see on a typical Carib' cruise. I've NEVER heard of a commercial air ambulance doing an evacuation from a cruise ship and only a few done by police/fire helos ... rare but they do occur and they have their own rules. My local sheriff dept has helos and just recently announced they now have the ability to hoist a person from the water in a rescue .... If over near UK or the Med .... different story and I dunno.