In the Karma video, we see a take off from the front of a kayak. Now I personally wouldn't trust landing back on the front of the kayak afterwards since it's such a small surface area, but the point I got from that scene was that it was possible to take off from a floating platform and I must admit I was kicking myself in the back for not having waited for the Karma drone to come out if it meant being able to take off from a boat. The main reason I purchased a drone was to get aerial water footage and to have the drone follow the boat while underway for some good footage.
As I mentioned in this thread before, I took a trip to Bimini and was able to get footage but only from taking off from the beach, I never bothered trying to take off from the boat because it was pretty windy and the boat was rocking. Even while on the beach, I when it was arming and sitting on top of the carrying case lid, the wind i guess was causing movement and the controller warned me about movement being detected. That was some pretty sensitive detecting if you ask me, so I dont know if it'd be possible.