Your concern with the bilge is complicated. Other owners have faced it.
Here is an SBO link from 2010. The owners are discussing how to install a bilge hose loop for the boat.
In my recent thread "H23.5 centerboard/compression post leak", Mike (soling42) suggested water can enter the bilge pump outlet/through-hull when heeled over far enough. Sure enough, this is indeed the cause of what I hope is my third and last leak. I've attached pictures. There are only a few...
forums.sailboatowners.com
Here is an interesting review from Practical Sailor.
hunter-23-5
You might find the attached personal manual, created by an owner, helpful. "
McDonnell Hunter 23.5 Manual"
Looking at the boat in profile, I drew a line set about the lowest point on the boat hull. The rationale is that water will seek the lowest point in the boat. This is usually where a bilge pump would be located. On your boat, the water ballast tanks and the shallow hull draft complicate this.
It appears to me that incidental water will find its way into your boat. It will move about the shallow bottom of the hull. Here are some ideas on how you might deal with it.
Incidental water (leaks, rain, wash-down) does not stay neatly in one sump (bilge). It tends to collect:
- Under the cabin sole, around the centerboard trunk and ballast tank
- In the spaces under the settees
- In the aft berth under the cockpit
Limber holes in the structure let some of that water migrate toward the center, but owners frequently note there is no single deep, well-defined sump (bilge), the way a conventional keelboat has. The factory automatic bilge pump sits in this central area; its discharge through-hull is on the hull side and is relatively low, which is why heeling can let water run back through the pump. (The SBO link above discussed this issue.)
Practical access points owners use:
- Flip-up lid / bottom companionway step — ballast fill/drain valve and vent
- Cover plate at the base of the mast compression post — centerboard mechanism
- Under-settee and aft-berth hatches — stray-water collection spots
Because the hull is shallow and the ballast tank occupies most of the lowest volume, stray water will sit in several shallow pockets rather than one obvious well. Many owners add extra pumps or just sponge those pockets after a rain.