In the Cal
that I had the bilge was almost 6 feet deep and a foot wide by four feet front to back. No way could you get into it. I put the bilge pump and alarm on a flat bar aluminum
rig that I could lower into the bilge with the pump at the bottom and the alarm about 6 or 8" above it. If crossing open water and I needed to flood the keel
for stability I could turn the pump and alarm off. There was a secondary system with both pump and alarm that was mounted below the cabin sole
The boat I have now has a separate bilge pump in each of the 10 watertight compartments but only 4 have high water alarms. The Front and back on each side of the boat. If any of the other compartments flood they will not sink the boat, just soak everything stored below deck
. Another problem with multihulled boats.... Way more bilge pumps than other boats. You worry about one or two. I've got ten plus 4 high water alarms. However, these are very easy to jump down into the compartment and work sitting on a stool or box.