i have about a 2" hole right below the hatch boards into a space below the floor. i do get some standing water in that space, but never above the hole. (almost looks like a bilge pump could have been placed there at one time.) i believe the water comes from rain around the hatch boards. is this the area you meant as the bilge?
i don't have a bilge pump installed. i do have a hand pump, but i never had enough water to get the hand pump to draw. i have wadded up a sponge to get some of the water out. i have never gotten water above the floor even though the boat is mooring in the open lake and at times it rolls by as much as 45% during high winds.
i would check the cockpit drain hose and it's connection to the through hull fittings, as well as the fitting itself besides the fish finder. (if you need to repair either you will obviously need to have the boat out of the water) if nothing is leaking there, it may just be rain water but something to keep you eye on. let me know how you make out.