I've always felt that fresh water directed into centreboard/ drop keel cases should eliminate/ reduce growth (salt water growth) .We now own a RL28 and if this is original was Rob thinking along the same lines or was it just convenience . Our shower water is pumped into the centreboard case , we had planned to direct fresh water there but Rob was already there (if original design) .
Does anyone know if this is the case ?
I haven't seen that arrangement. I don't really see the advantage as far as antifouling goes as I had no problem with growth in the case of my RL28 that was in the water for 25 years, presumably because no light gets in there.
You say "pumped into the centreboard case" so I presume the outlet is above the waterline. That is a huge advantage for safety over a thru hull fitting below the waterline, particularly if the basin water also drains there.
I'd be interested if anyone else has that system.