Bob

I wish you were right as that would solve the problem. No. The tank
definitely vents outboard. I still can not find the source of the
water. Possibly, it could be a limber hole to carry water from the
forward part of the boat to the bilge pump sump area but I do not
think so. I have inspection access to the bilges forward and there is
no water there. A real puzzler. When, and if, I find the solution I
will post it here. In the meantime you seem to quite analytical
minded so I welcome any other ideas you might have. Thanks.

George

On Wed, 24 Jan 2007 14:03:20 -0800, Robert Salnick
wrote:

Is the 1" pvc pipe part of the vent/overlow for the tank? Many boats
have their vents inboard. I have a siphon start where the end of the
vent line is below the top of the tank, and the fill on the tank is
above the vent location (tank not level, boat heeled, boat not trimmed,
etc). If this is the cause, the siphon should only start when the tank
is filled, and should stop when the water level drops below the vent
location on the tank...

bob