Rick and Jody:
On VESPER, V1868, I installed a float-operated bilge pump very much as you
described; on top of the fuel tank. I bolted it to a piece of 3/4 inch wood,
sized and shaped so as to wedge into place with its sides against the port and
starboard sides of the bilge walls. I ran the pump discharge overboard through
a hole I drilled on the starboard side of the hull, and with a check valve in
the line to avoid any chance of water coming in when on a very "well-heeled"
sail. Also, I wired this pump directly to one of the batteries. This saved my
boat from taking on a lot of water more than once, and kept the batteries from
becoming salted even more.
I also had the manual pump under the aft end of the cockpit sole, on the port
side of the tiller. I mounded the pump handle on that little bulkhead just
aft of the tiller. Please remember to mount the clips for the bilge handle so
they won't interfere with the operation of the pump, or the hand that is
operating the pump.
Good Luck ................Ed