if the water's 50º, try one of the RipCurl thermal shirts
under your wetsuit instead of another suit.
uhh...can't remember what they're called, but they have
a titanium lining, they're like a long-sleeved rash guard.
Or maybe one of the Oneill thermal shirts; they're like a
super stretchy thermal that's made to wear under suits
in cold water.
I did the RipCurl trick under my 3/2 Excel in SAnta Cruz.
worked too well; kept me just a bit too warm.

