Why risk it? if this is the work you need a UAV for then I would purchase a waterproof UAV that is what they are made for, plus I would only use a cheaper Phantom equiped with Liquipel. see link below.
Of course if money is no object then do what you want when you want.
Liquipel is not available in my country. And Amazon doesn't deliver in NL as well.
But what's the extra risk? Only that you get a few drops on your camera, but a lot of us also fly with a couple of raindrops. If you land normally there's no spray at all. And besides, if it ever would fall down for some reason I would rather have it crash on fresh water with the floats than on land without.
I would not use the floats to take off and land on water always, only in emergencies. As a last resort.
There is the risk of serious wetness when you land with a splash. But I never landed that hard on land so why would I do that on water? Liquipel on the X3 camera would be a great option for that matter.
Catching, while operating from the boat, is always the first option. Have been catching the I1 on the boat for a number of times and it works great and with the right procedures, safe enough. The catcher wears a safety harness and live line, helmet, sunglasses, gloves and a live vest. But being able to land on water in emergencies or in forced auto landing, would be a big reassurance.
Even when flying from the beach over the lake, it is great to know it can land on water.
I took a test flight yesterday over land with pool noodle floats (measured they could keep 3.4Kg well afloat), after floating the I1 in the bathtub. It flew without any problem. In Atti it reacts quicker to wind drift of course. The battery also empties a bit quicker, maybe 10% less flying time. Taking off and landing is actually a lot safer with the floats, also on tall grass, I noticed. It is a bit more sluggish overall and the stopping is a bit harsh. But nothing really serious. Footage still looked good.
With the motor arms up it looks really badass. The X3 shows the nose of one of the floats but only in sudden harsh turns. With 20% zoom they stay out of the image all the time. The floats are attached very safely with velcro band all around. Feels quite solid and safe, even to grab on when catching.
They attach in a matter of seconds with the velcro.
I will post pictures and video once i have something to show.
