Peggie Hall wrote:

That said, I would not connect ANY clear hose to any thru-hull. 'Cuz
IMO, whether it's hoses or anything else, you can never regret erring on
the side of caution. And fwiw, I've NEVER seen any clear bilge discharge
hose. Boat builders are very cost conscious...if there weren't a good
reason to stick with marine-grade bilge pump hose, they'd use something
else that's cheaper. And also fwiw, I wouldn't use corrugated hose for
anything on a boat, anywhere.

But that's what I'd do. It's your boat...your choice.
Hi Peggy:

Thank you for the fast reply.

So If I under stand correctly, "below the water line" indicates
100% emersion 100% of the time? What about a bilge system that
discharges through an above the water line (6") through hull? Never
wet until the pump starts and then its empty? Would that situation be
considered "below the waterline?"

On a slightly different thought, one thing that I do hold strongly, or
was that strongly hold, is that the maritime industry is permeated with
tradition. In fact, "tradition" is a selling attribute for many
companies. Do not want to try anything that is not test by time, ya
sure, ya betcha. The problem with that is who is going to take a chance
and test it first? And as far as boat builder are concerned, I agree
they are there to make a profit. COuld be that the pvc hose just takes
alttle mroe time to install because it is more robust that the the
stuff installed at the factory. I know the white 3/4" hose on my new PH
2 could not take the slight bend to the bowl. The hose was colapsed at
the radious and restrist the flow. I "up graded" that factory OEM
asap!.

I looked over the specs for the pvc. No corrugation. Its very smooth
inside. Temp, PSI, flamibility, 1/4" wall, it all looks good. I was
reviewing the different industries that use it in some very horindous
applications. Looks tough! I just belive that looking outside the
marine industry is a reasonable thing to do IF the product is designed
for similar applications but not called "marine."

Silaprene adhesive/sealant is an excellent example. Used in the
trucking industry for decades to "glue" 40' trailers together
only recently "discovered" by sailors to bed through-the-deck chain
plates.

So your apprehension to use the pvc hose for a bilge system is based on
what engineering specification?
Bob