No. We have no problem building that part nor the double flapper one.
We are looking at a check valve that has a swinging door inside a big
bronze or stainless casting...it a
plumbing part. Pretty heavy but so is the skipper.
We’ve seen plastic one way valves but the
bronze plumbing valves are really strong. Not sure if they would close completely but if vertical, they probably will
work. The duck bill valves are available in
medical grade silicon in every size from
China but we’d have to buy 100.LOL
Must be some
DIY way to cast one up.
Thank you for the reply.
The manatee crew