Preparation is the key to ditching survival
If you fly around the coast or over water a lot you should be prepared to execute the the proper procedures for ditching. When teaching beginning Air Force pilots to fly the T-1 aka Beech 400, I'd routinely give them a ditching scenario as an emergency procedure and have them execute the EP in real time with me timing their response to water impact. Very few got it right and hopefully they learned the importance of knowing the aircraft's best glide speed, how far the aircraft would glide per thousand feet, and the basic steps of what to do in this emergency and not rely upon the checklist. Even professional pilots aren't always prepared. Sully Sullenberger and his co-pilot forgot to close off the baggage compartment exhaust valves before impact and as such after ditching in Hudson River their plane filled full of water. Navy pilots routinely practice getting out of a ditched aircraft inverted with stuck door/canopy.
Here's great 2004 article on a successful ditching. I would image this RV-8 pilot thought a lot about ditching since he flew out of the Hawaiian islands.
http://www.aero-news.net/index.cfm?do=main.textpost&id=85c0322d-8d8e-4f7b-bada-e82df2e33326
Pilot Survives Ditching And Shows It Can Be Done
Most pilots fear ditching an aircraft into the ocean but one aviator recently proved even the worst of situations can be survivable. Bob Justman's RV-8 was cruising at 1,000 feet over the beautiful waters surrounding the Hawaiian islands on Sunday morning, when at 8:52 a.m., he lost engine power as he flew to Lihue from Honolulu.
Justman promptly radioed the Honolulu ARTCC and set-up for a ditching approximately 60 miles from Oahu. Fortunately, he was under ATC's watchful eye as he made a last call about 200 feet over the water's surface. More importantly, his training would prove to be the key to his survival.
Once into the water, Justman immediately went to work getting out of the airplane, which had moved into an awkward and potentially dangerous position.
"After impact the canopy closed and the aircraft inverted underwater, trapping me in the cockpit," Justman explained. I released my shoulder harness and seat belt and worked at opening the canopy while underwater for over a minute. Miraculously, the canopy partially opened ... and I was able to eject myself from the cockpit just before the aircraft sank," he said.
Fly safe,
George