Moving extending hull LWL (Catamaran)

Have there been any experiments or attempts at adding mechanical moving hull extensions (likely catamaran) in either the bow or stern? I'm thinking 44ft livaeaboard that can extend to 50ft+ in open water.

 

For what purpose would you want to design a 6' extension. I can only think of a few and none are worth the headache. The extension has to have a home which translates to lose space.

 

Brings to mind the military planes with folding wings that tucked in to make a delta for high speeds.
Displacement hull that has extendable planing surfaces?

 

Yes, and they all failed miserably.
But I'm sure you can make it work.

Why do you ask, are you designing one?

 

CapnD- maybe something like this? I suppose they could be deployable, leaving a vertical step when out, and a lower prismatic stern when in. Possible SlopeCarver is looking for length in waves, better light air performance, or cleaner release in the bigger stuff? Dunno, but horizontal stern wings have been lurking for a century or so….