Hi All

Some of the early B-Class development cat designs had sliding seats ,-read Reg Whites books -in U K -on early C-and B class development--time frame 60s -70s ,-
PROBLEMS ARE WEIGHT -complexity and stationary for -aft location .-

One of the most interseting versions of that were on the later 80s Worrell designs in the open class -
One had a 10 ft fold up rack mounted on the outside edge of each hull on a traveler ,-
It looked a little like someone had gone wild with an erector set and put it on a Harken traveler .
--but ,-simple math is ,-put a 200 lb crew 10 ft out further 200* 10 -thats 2000 extra ft lbs of righting moment holding the sail forces ---talk about more beam !!

Another version of 10 ft fold up rack just used an alum. pole and mesh seat at the end --kind of reminded me of a giant fly swatter in appearance --
Both were very effective and fast -

Seems most everything has been attempted in one form or another ,-its refining those ideas and concepts into working form sometimes requiring connections of other ideas and invention that eventually makes them viable .--its fun stuff,-but expensive and time consuming ,-and not alaws marketable .
There are some great books on curious yachting inventions thru-out history ,-and room for more -one on cat design or multihulls would be very marketable today !!
Patten searches are a great source ,and fasinating looking at old diagrams dating as far back in the U S as the early 1800s -
Recall the ill fated giant multihull round the world racer with two masts ,-one on each hull ,-as the tri foiler has ,-You can find this pattened as applied to a square rigged ship in the early 1800 for example -many many more
The same ideas brought back in modern form and refined again and again .-eventually they work !!