Charlie:
We use a wash down pump, of which there are many. Our is,
www.defender.com/product.jsp?path=-1|51|299222|315122&id=743643
If I were doing this again, I would get a stronger, or more GPM rated one. This may sound like a lot at 4 GPM, bbut in wind, the water pressure is overcome by the wind and you cant spray upwind to the anchor chain.
Our pump is mounted in the cabin sole hole near the mast. The pick up water comes from a T-off into our Air Conditioning thru haul. The hose then runs under the v berth to the bow, where it comes up to a hose fitting. This is the common solution.
Hayden