Short version: lost both engines over Bahamian waters with 2 passengers on board, ditched my 1977 337G successfully, rescued by nearby ship. Coverage with pictures by a local news station is attached below.
After the FAA completed its investigation and decided that no sanctions were warranted I wrote a lengthy post on this Message Board about what happened but I've used the Search function to find the post so I could provide a link and can't find it. A briefer version from memory follows.
Was flying at about 10 AM from Great Harbour Cay to Miami, about 140 nm, with 2 passengers. About 15 minutes after takeoff and at about 6,000 ft the front engine quit from what seemed fuel exhaustion. I had fueled in Miami the previous afternoon so I knew I had enough fuel. Wondered if it was a clogged line from that tank or that fuel had been lost from a leak in the tank. Crossfed, restarted engine, started to climb (just in case) and advised traffic controllers. About 10 minutes later, now at about 8,000 ft, both engines quit, obviously from fuel exhaustion. Was able to restart the front engine from its original (left) tank*, advised controllers, and started briefing passengers and making ditching preparations**. A few minutes later the front engine quit. Glided for about 10 minutes, asking controllers to dispatch the Coast Guard, while keeping them and nearby aircraft informed of my coordinates. Was fortunate to see a cargo barge/ship ahead and ditched about 4 blocks in front of the ship.
Seas were 2-3 ft, ditching was routine (meaning impact was as expected: rough but survivable), and all 3 of us exited with only modest difficulty through the upper clamshell door which we had opened just before impact (the only unexpected thing was that the torrent of water coming it made it difficult to swim out the door). There were no injuries except for a shallow cut on my head, which you can see in the pictures, perhaps as I went through the door. The wings of the aircraft remained floating for about 2-3 minutes, then the whole aircraft slowly sank. Ship picked us up about 10 minutes later.
No one knows why this happened. Some believe that fuel was stolen overnight, given that at the time (2014) a gallon of fuel in the Bahamas was $6. And I should not have relied on the fact that I had fueled the previous afternoon and should have checked the fuel gauges carefully. The aircraft was not insured. A friend bought industrial airbags and tried to lift the aircraft -- it was at a depth of about 20 feet -- and drag it to Bimini about 20 miles away but was not successful
* If you've learned about the fuel system on Skymasters, you know that part of the fuel going to the crossfed engine returns to that engine's normal tank. So when the front engine was being fed by the right tank, some of that fuel went into the left tank.
** Since I mostly fly over water, I've done a lot of research on ditching and have a page on the subject at http://www.skymasterus.com