[mitiempo]

.... in my mind it will work great.... think a hose screwing into the deck fitting then twist locking to the pump and a fixed 5 foot discharge hose with a weighted end to keep it pointed down and use it to pump the tanks when needed not every time you use the head

A lot more complicated than an outlet plumbed to a seacock. Open valve, pump, close valve. No muss, no fuss - won't even have to wash your hands when done.

 

[mitiempo]

Actually suction not pressure and with the caps on there is no mess how do you think they pump you at the docks

After they pump you out at the docks they deal with the hose.

For a foolproof pump use a manual diaphram pump

 

[mitiempo]

Well, we figured that we would avoid having the suction from a pump-out station pulling the waste through a pump.....

The deck pumpout should never be plumbed through a pump. It should ideally be through a dip tube through the tank top. Second choice is a dedicated outlet at or near the tank bottom.

 

[mitiempo]

Here are the links to Mainesail's how-to:

Seacock & Thru-Hull Primer/Pre Information Photo Gallery by Compass Marine How To at pbase.com

Replacing Thru-Hulls and Seacocks Photo Gallery by Compass Marine How To at pbase.com

Seacock Backing Plates / Alternate Method / No Through Bolts Photo Gallery by Compass Marine How To at pbase.com

Installing A Seacock & Thru-Hull Fitting In A New Location Photo Gallery by Compass Marine How To at pbase.com

 

[mitiempo]

I would use either G10 or fiberglass and epoxy it to the hull.