You need to check that bilge pump and repair or upsize. No way should a bilge pump run for hours without being able to pump out a fishing boat unless it’s seriously undersized or not working properly.
The other issue I see all the time is undersized wire running to the bilge pump, so the current is not available to pump to the stated capacity. I would never run anything less than 14 gauge wire to a bilge and that’s the absolute minimum. For bigger boats, I’ve run 12 or 10 to each pump, do whatever the pump size and wire run call for.
Also, corrugated discharge hose reduces pumping speed and efficiency. Smooth is always better. And with all critical marine systems that involve hose clamps, stainless clamps X2 on every fitting end. Never rely on a single clamp and never, ever use pot metal automotive clamps in a marine application.
Grouse