"Dave" wrote

As to the on-deck filler, I'm not sure it's worth the effort. My old
boat
had a fill system like yours, and it just wasn't that much of a
problem.
It's not as if you have to fill the FW tank every week. My present
boat has
an on-deck fill, and while it's nice I don't think I'd go cutting
holes in
the deck to install such a system if I didn't have it. I'd suggest
the
effort is probably better spent putting a second vent on the holding
tank.
Since you're replacing it there will never be a better opportunity.

My deck fill is inside the anchor locker. I find it easier to run the
water hose through the forward hatch and directly into the tank.

Scotty