I did try out a few things with this and it might work.
If you fly an ordinary plane into the ocean with wheels up you crash.... nothing new here.
BUT.. if you have the wheels down you can go through the surface of the water to be fully submerged and come back up again without any problems!!
As long as you are not under the surface for too long that the pilot dies.
I think they thought of this when they were making the ofp engine. They realised most of us are going to be pretty bad at bringing these birds back to the ground in a stylish manner, so therefore when gear is lowered, the damage taken is reduced.
Thats my theory anyway!
;D
A seaplane doesnt have to worry about wheels, it could just have floats... which are fixed in place.. so dont need to be raised. That solves the problem of crashing on impact with water!
Now.. I thinking you might be able to use the 'canfloat' command to make the plane float on the surface.
(I dont know if this would work, I didnt worry about checking this bit yet.)
So there is a chance that it could be possible!
Dont hold your breath for this addon though... this is just somthing that I thought I might have fun making after I make the stuff I REALLY want to make.
Unless someone else wants to give it a go!