With regards to the water rescue from a yacht (or similar type thing), the Australian Search and Rescue (AusSar) helo crews are now using a thing called the Droppable life Raft System (DLRS). Basically, we approach the vessel like a hi-line and lower a line to the boat (also on the hook lowered is a bag with some strops, a rescue freq radio and a set of instructions). The line is attached to a solid part of the boat with a carabiner type hook and the helo backs off a wee bit and a life raft (which is attached to the other end of the line) is thrown out of the helo. As it falls or after it hits the water (depending on the height it was thrown), the life raft inflates (and a weak link on the aircraft means that the liferaft is never really attached to the aircraft at all).
The survivors then use a carbiner harness (they attach themselves on the lifejacket at one end) on the previously lowered strop and attach this to the line between the vessel and the raft. They then go for a swim down the line until they bump into the life raft. There is enough slack in the harness line that the survivor can now get into the life raft before unclippling from the rope (and then clipping onto the liferaft so safe again).
Now we just winch out of the raft like normal (overhead winch with no swimming to the raft). By having the raft at about 150ft from the vessel, we find that the vessel gives a good hover reference (much better than nothing) over the raft. A simple and effective system.
We used to use a RN/RAF/RAN sytle highline but this AusSar method is really very good (and they pay for it, and we do yearly currency rides with AusSar to prove our proficiency).
The biggest thing we find is the line on the way down has the biggest tag on it saying ''DO NOT THROW AWAY'', but the survivor will get the bag (and hook on the end of the line) and then throw away the line
, so we have to put the line to the vessel again so they can connect it.
Otherwise
Cheers from WA