Seaplanes?

"Doug" wrote in message
ups.com...
The ability to land in rough water is limited by the hull strength.

Yes, that too. But control on the water surface is at least as important as
not breaking something. The hull design also affects the forces
experienced; a shallow hull decelerates more quickly, transmitting higher
forces to the airframe.

Sheer strength is always a factor, of course...but that's true of every
aspect of aircraft design. It's often not primary, and I disagree that it
is here. Hulls intended for rough water operation are designed with a
steeper "V".