brad wrote:
Has anyone had any experirence with 50 gal flexible ware tanks in an
offshore sail boat?
Good or Bad

Not in an offshore sailboat, but I have some experience with
flexible tanks for potable water in other applications.
They're great, as long as they are installed into the
structure & system properly.

Fill, supply, and vent piping/tubing needs to be mounted in
such a way that they rise & fall with the tank as it
fills/empties; without placing any strain on the skin
fitting into the tank. This is the most common failure point.

The tank itself needs to be properly secured so that it
never folds on itself while filling/emptying. It also needs
to be padded so that it never has abrasion. They also need
to be protected from puncture, this one is obvious and the
modern tanks are surprisingly tough.

Solve these problems, and flexible tanks (commonly called
bladders) are better in almost every way. But they ain't
cheap, either. Instead of 1 50 gal, consider two of 25 each.

Fresh Breezes- Doug King