Wayne.B wrote:
On Sat, 20 Jun 2009 10:31:29 -0500, Richard Casady
wrote:

Rule makes a 3600 gpm bilge pump. I figure I could plumb one to a
couple of transom nozzles and have a couple of miles worth of
emergency propulsion for my 22 ft fish/ski. You also plumb it to a
hose at the bow, to wash off the anchor and rode. I used to use a 20
pound or so Danforth with a fifty foot rode to anchor in 20 ft, mud
bottom. I always buried it with the engine. Adequate for a 12 foot
duckboat. Also used it with a jet runabout. No cleats, you tied to to
the lifting eye, there were chocks. Same line also served as the dock
line. One foot of 3/8 line per year, for two boats. Cheap.

Bilge pumps are designed for high volume and low pressure. A wash
down pump needs just the opposite. There are several 12 volt pumps
suitable for wash down but a lot of bigger boats are using 110 volt
well pumps because they are durable and a good value.

Continuing the good advice here...

Mount the wash down pump pretty low - the closer to the water line
the more pressure you'll get from the output.

Sure, they say they can self prime 6 feet or more, but that reduces
pressure at the output.