The jet seaplane problem

What was one of the most implausible ideas tried in naval-aircraft design?

A Saunders-Roe jet seaplane, because it asked a high-speed jet aircraft to take off from and land directly on a wave-affected surface.

The jet seaplane contains a fundamental operating contradiction. A jet benefits from high speed, but a flying boat must meet an irregular water surface during takeoff and landing. Waves impose impact loads and control problems unlike a prepared runway. The Saunders-Roe effort shows how a naval operating environment can undermine the attractive performance of a propulsion system.