I sail a number of boats with very shallow bilges (not the cat in the avitar). At 1 1/2 inches there is water
on the cabin
floor. Obviously, the common float switch range and bilge pump
set-up is less than satisfactory (on at 2 inches, off at 3/4 inches).
ABYC has standards for sump pumps on recreational craft. They do not require a UL listing, but the pump
does need to meet a variety of requirements.
- Ignition protected (but not NEMA explosion proof).
- Run dry period without excessive case heating.
- Numerous installation requirements.
- Screening is a common sense requirement.
The smaller the pump
is, the easier it is to meet the second requirement. Some only pull an amp at full load and less MT. It's hard for 12w to get hot. No, a tiny pump won't move much, but you can always back it up with something conventional and large.
(A small pump, like this, can easily work in the 1/2-1" range. Still not dry, but below the floor.)
Pumps can be run on timers with very short intervals. The auto pumps work
on this principle. Not the best thing for seals
, but they probably aren't dry and there is little heating
potential in smaller sizes. No float switch.
I'm aware of the Arid Bilge
System. Basically a tiny, automated, reversible Shop Vac.
Anyone rig something up for very shallow bilges?