Almost had a heart attack.

[Bushwacker]

Filling baitwell with foam is just a band-aid that eliminates a handy feature and may create other problems! Plus if you already have so much water in the bilge that water is coming in the scuppers, I doubt that a few pounds of foam would make enough of a difference to stop it from sinking. Better to address root cause of problem (bilge pump/switch reliability!) with dual independent pumps and maybe a high water alarm. That's cheap insurance for any boat left in the water all the time. BTW, Rule makes a float switch that's inside a box to keep it from getting jammed in off position by bilge debris, which eliminates another potential failure mode. You could also consider rigging a counter or an hour meter to the bilge pump, because a good pump can mask a leak, at least until it runs the battery down! If it's coming on a lot, you need to know that. Another cheap visual high water alarm is a bootstripe! If you learn where it is relative to waterline with a dry bilge, a quick glance will tell you if boat is sitting lower in water than normal! Sounds like your dad had already picked up on that.