On Thu, 17 Sep 2009 09:33:19 -0700 (PDT), Frogwatch
wrote:

Bought a 3700 gph Rule pump for the Tolman just in case I take a lot
of water. My normal bilge pump is a 750 gph one. I intend to find
some smooth bore hose for it and some oversized wire to power it.
Downside is, it was expensive and I will probably never use it. Might
even get a dedicated battery for it.

I think that's a good plan, with a couple of caveats: It's a good
idea to derate the capacity of bilge pumps by 50% or so to compensate
for head loss and hose friction. It's also important to remember that
bilge pump float-switches have a proven record of unreliability,
leading to the need for a manual override switch, and possibly the
desirability of a second, totally separate, pump/float-switch combo.

No one has ever complained about having too much bilge pump capacity.
If the cockpit of an open boat swamps with big water you are only
seconds from a loss of stability and capsize.