Why are so many modern vessels built with a single hull? To me it's always seemed that a catamaran is far more stable, and would be able to hold a larger flight deck for a carrier or offer a more stable platform for battleships. Why is this the case? And this being AH.Com, how and where could we see catamaran capital ships being used?
catamarans are only 'more stable' up to a point ...
European ship and boat development didn't pick up on the multihull idea until exposed to multihulls in the south pacific
arguably a SWATH (small waterplane area twin hull) carrier is concievable but it would be a radical move ,also some of the benefits of a multihull are in the fineness of the hulls compared to the deck area so for steam ships with bulky powerplants and the requirements for huge bunkers for solid (coal) or semi soild ( heavy fuel oil) fuels ...
a swath or trimaran Invincible class 'through deck cruiser' with COGAG propulsion ( running on kerosene type fuels) would be an interesting proposition ... or a Swath or tri version of one of the big nuclear post WW2 US carriers ... a SWATH commando carrier that lowers her landing craft from between the hulls while CAS Harriers / F35s and Helicopters fly fro mthe deck would also be a interesting craft.