Speaking of moving vehicles and people in the sea - the UK SBS have a rather interesting technique for divers getting picked up by a moving submarine.

The divers wait in two teams separated by a line, they notify the sub that then raises its periscope and steers between the two groups snagging the line. The divers then climb along the line to the sub.

[NB This was what they were doing ~1970 according to Paddy Ashdown]

Corona used a C-130 system as well.

http://en.wikipedia.org/wiki/Mid-air_retrieval#/media/File:C...

Thinking about it, it might be a weight constraint to cause them to use a helicopter. The sudden capture of an object weighing a few thousand pounds by a plane flying 350 mph could be too dangerous.

The major difference between Corona and Fulton is that Fulton is not mid-air (and therefore involves the thing being retrieved getting a saltwater bath).

There are some pretty big helicopters out there that wouldn't blink at picking up a load like this. The Chinook is used for cargo transport quite frequently: http://en.wikipedia.org/wiki/Boeing_CH-47_Chinook