Pivoting leeboard on a catamaran

[Periwinkles]

Has there been a catamaran designed with either one or two pivoting leeboards on the underside of the bridgedeck attached to the hull?
Ideally the pivot would be 1/3 from the top of the boat and the top of the leeboard would fit in a slot when in the down position. That would be stronger than having the pivot on top of the board. Similar to what is done on some dinghies. See photo attached

The advantages over LAR or daggerboards would be numerous

Kicks up when it hits something
Out of sight for those finding leeboards ugly
High aspect ratio
No crash box needed
Hits the water earlier than LAR or daggerboards since it isn’t placed under the hull

What would be the disadvantages?

 

[Skip Johnson]

Seems like a nice idea, may have been done before but I've not seen it.
An added advantage is the possibility of asymmetrical boards. Now that I think of it Brian Eiland has some stuff on a central 2 part CB for the same reason.
A disadvantage is having to make two boards.

 

[oldmulti]

Periwinkles. Some multihull designers expressed an opinion on leeboards on the following thread: Leeboards on coastal cruising sail cat? | Boat Design Net
Leeboards on coastal cruising sail cat? https://www.boatdesign.net/threads/leeboards-on-coastal-cruising-sail-cat.63550/

There are several bigger cats that have used leeboards with some success. They all comment on noise, but the rest is OK.

 

[cando2]

Periwinkles, I have been considering your idea for an internal hull side leeboard and I like it, though I personally have little concern for appearance on the outside. Regarding possible disadvantages I see few, but building on Skip's idea of using asymmetric boards I have a couple of additional thoughts: a flat could be introduced on the internal hull side to just below the pivot point to make a more streamlined interface to waterflow. This might also mitigate water turbulence noise (and vibration) along with its being under the bridge deck. Regarding the deck slot that supports the upper board end that would work just fine and would be an improvement and would work great on an open bridge deck; however, on an enclosed bridge deck not so much. Perhaps the boards could be shortened and radiused (off the board's pivot point) and matched to a radiused encapsulating block bolted to the flat hull side? That way the board ends would be supported the full 90 degrees of swing. This setup need not pultrude into the bridge deck house and might make for a flat transition to steps in the hulls. Thoughts?