There is a temptation to have the plane taxi into the water on its wheels (from a boat launching ramp, for instance) and then retract them once the plane is in the water. Then reverse that sequence after landing to taxi out of the water.
I have a mental picture of the Seawind taxiing down the boat ramp and just going on and on until it is completely submerged.
You would just have to make sure the nosewheel doors are sealed up tight and make sure the wheel wells in the wing are not open to splashing water . (There will be alot of that.) You would not have to take them out of the airplane, although given the added weight, that would be a good idea.
Jim