I'll post my story as I've lost my MP a month ago while flying from a boat. I did it for a charity as a lady was swimming around HK Island (in 15 hours straight) for donations. I have had experience flying from a boat before while scuba diving in the Maldives, so this was not my first time. The crash had nothing to do with the drone performance but only my situational awareness.
I did my first flight fine but here's something to remember. It was not a big boat just a small catamaran so I didn't have a lot of clear space to take off. I was just about a meter behind the drone as I started the the motors. I didn't intend to take off immediately and just wanted to check things are ready. However it was quite choppy that day and the boat bounced up and down quite a bit. Sensing the change in altitude the drone took off by itself and hovered. As the boat was moving so I was moving towards the drone. Only a quick ducking and pushing the sticks to go up and forward immediately avoided am accident to my face. So give more space and get prepared to ascend as soon as you have the props spinning if the water is choppy. That's my first bit of advice.
I dare not do hand catching (after watching some accident clips during my phantom 2 days) so landing was also tricky. There was a bit of netting in the front of the boat (for sun bathing but no sun that day) so I cleared out that space for landing. The boat was moving so I had to matched the speed but successfully landed it, although it took an intense minute to got it right.
I took some rest until upon a cape where the sea was really choppy with some rocks getting high waves, so thought I could get some epic footage of the lady swimming in front of those rocks. So I took off and this time ascended away. I took some good shots of her. The problem was we had a second sail boat which was her support ship that followed her for the whole swim. I already reminded myself during the first flight to be aware of the second boat and stayed away from it. But the second flight I was really focused on getting the good angle so lost track of it. The drone and the second boat crossed path and it hit the mast. As soon as a warning came up on the screen I looked up and saw it tangled with a rope and started dropping. I tried the CSC and hoped motors would stop and not hurt anyone on the boat and the drone would just fall onto the deck. It did but further rolled into the water. Watching the cached video is disheartening as I can get hear my "Uh Oh" and the swirling down. It didn't record getting into the water but probably connection was lost at that point already.
Well flying from a boat is definitely possible and can be a lot of fun too. But must be a lot more careful and more aware. I'd say normally we won't be flying that low but I had to film the swimming so must be close to water and therefore at the height of the mast.
I'll be going for a diving trip in the Maldives again in 2 weeks so I just got myself a MP2Z and had my first flight yesterday. With the zoom I don't need to get close to dangerous range again. So be careful, be safe and enjoy!
Here's the edited video from that swim: