I see you've just joined our merry band of
boat owners...welcome aboard!
You might start by replacing that "paper thin" bulkhead with something thick enough (1/2" would be thick enough) to let you cut a proper access
hatch in it--maybe even a couple of hatches if necessary to provide access to both ends of the tank or maybe a macerator
pump or vent line--which you can trim with something like picture frame moulding if cosmetics matter, along with thin sliding
panels to cover the openings. You decide where and what what size they need to be.
Just a "top of the
head idea...others may have better ones.
As for why
Beneteau designed it that way...boat builders rarely if ever DESIGN sanitation systems. To them sanitation systems just add cost that contribute nothing to the value of the
boat. So they put them together as cheaply as possible without regard for the fact that, unlike
water and
fuel, sewage must be managed and count on the problems that arise from their failure to acknowledge this waiting until after the warranty has expired to make themselves known.
--Peggie