40-50 gallons of mystery water

[NeverEnough]

Hey all,
My old man (father) got his hands on a 2001 Wellcraft Martinique 2600 that we’ve been restoring for the past year or so. We’ve gotten it to a point that we aren’t fearful of sinking and have taken it out for extended amounts of time and things seem good.
We’ve got one big mystery though. Just as we are about to pull it out of the water we run the bilge for around a minute or so and then put it on the trailer and pull the drain plug once on shore. Once the plug is pulled we get what he estimates to be about 40-50 gallons of water. This doesn’t make sense to us as the bilge runs dry but also that we can’t see water anywhere else in the boat’s engine compartment. My theory is that the bilge sits in the engine compartment and the water we see pumped out through the Thru-hull is just that, engine compartment water. I also think the drain plug connects to a “subcompartment” that is below the engine compartment which we cannot see or access other than through the drain plug. Any truth to this? Does anyone know if there are “hull drawings” online somewhere that I could see a cad drawing of the hull?

[CptBill]

Welcome aboard, since that is a 2001 it was built by the original Wellcraft which went out of business in 2008. First start looking at your forward bilge compartments and see if there sealed off or have a hole at the bottom for water to pass through or if there's a forward bilge pump. then check your fresh water tank for leaks

[danoB]

Thanks for the reply. appears that our gimbal ring and bearing have a problem and a couple of seals in that area may be bad.

[CptBill]

If it's a VP set up make sure you check the "Y" pipe seal, I've had that as a mystery leak on a past boat(still think VP's are the best set up)

[danoB]

Sorry, but what is a VP set up?

[CptBill]

Volvo Penta