Glassed or bolted/screwed?

[ebb]

Have to wait til a Commander replies.

All I can say is that if the nomenclature is correct, no scupper is ever
drained into the bilge. Cockpit drains may drain via hose to fiberglass
THRUHULL pipes glued into the 'bilge'. Ariels had no seacocks for
these drains that were well below the waterline, but cracks in the
glassing or in old hose would of course be serious. This flawed system
should always be wide open for visual inspection. The connection of
hose to hull fitting should be completely visible and accessible.
It's also possible that leakage could begin at the fitting-to-hose just
under the cockpit.

Some boats have glassed in or separate hose leading deck scuppers
from drains in the side decks by the cockpit. Scuppers are in the deck
next to the toerail. They lead inside the hull and exit at the boottop
just above the waterline.
The Ariel I have were all fiberglass and polyester, no hose, no
discernable thruhulls. They were built-in and part of the hull.

The rot you mention in the aft bilge of what I assume is the cockpit
sole, might be a separate problem from your thruhull scupper
drains. There could be other sources of leaks. Former owners
might have attempted to fix them??
A Commander skipper will have to answer.
Assume rot can only happen if fresh water in quantity was left high
enough in the bilge over time to soak the cabin deck causing it to rot.

In the Ariel the cabin deck was tabbed in plywood. Fiberglass in
strips was pasted on top of the wood at the hull. If you have no
cabin furniture built onto this deck, which I believe you should not
have, it would not be too much of a problem to replace the old with
a new piece. The best LEAST MESSY tool for that would be a Fein
occilating Multitool using a bimetal dogleg blade.
If you haven't got an extra $750 for the tool, HarborFreight has a
decent one for $39 (?). It's the quality of the blade that's important.

Imperial Universal (fit any occilating tool) BM coated StormBlades:
Iboat 330 and 340 are the only bimetal I used to find. That old
polyester can be plenty tough -- but you can carve off most of the
tabbing Pearson used to paste the plywood deck onto the hull
without having to use a grinder. imco

Best of luck...

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