But since you say there are no apparent leaks, why don't you spend a few hours on the boat with the bilge floorboard removed and the automatic pump incapacited. Assuming that like all of us you have 0.5" to 1" residual water that your pump can't pick up, mark the level with a grease marker, incapacitate the float switch with a weight, leave the floorboard open, crack open a cold one and do something else for the next few hours while the boat is level. Checking your bilge from time to time. If after 2 or 3 hours the level of water is still the same, re-activate the float switch, re-install the floor board, crack open a cold one, smile and forget about it. If you are still worried, haul out and inspect the keel/hull joint. If you hit hard enough with the keel (unlikely at idle speed), that is most likely where the infiltration will take place.Good luck
get yourself a mask and go for a dive...if the water is freezing you can get a wetsuit at a dive shop...a rental for about 15 bucks a day. if you don't have leaks you will at least be able to see any damage and how much bottom paint is gone and then decide whether to haul her.if the keel is lead it will just deform as it is so soft. if it is cast iron it will crack or chip off. your not alone, i've hit a few things in my days also.good luckd
At idle speed the boat can do, say, 3 knots, and at this speed a whack on the lower front of the keel will kick the back of the keel up squishing the sealant. Depending on how much sealant there is and how hard the hit was this could open up the keel to hull seal especially at the aft end. Suggest trying to tighten the keel bolts and see if the aft keel bolt takes up some slack. If it does then this should stop any leaks. The keel to hull joints are pretty strong so unless it was wacked really really good you should be able to wait until the next haulout to get the keel to hull joint fixed (epoxied) and the front of the keel re-epoxied and barrier coated.The suggestion about checking for water infiltration is a very good one but afterward I'd still try to tighten the keel bolts anyway.
Sorry to hear about your run in with the bottom... I would suggest that you either haul or at least send a diver over the side to look at the bottom of the keel & your hull to keel joint. Good luck...dave
The main thing to worry about is any damage to the hull from the diagonal impact. This would show as stress cracks on the inside of the hull at the forward and aft ends of the keel. If you can't visually inspect this area from the bilge because of a liner I would haul the boat. Also, if the keel is bedded with 5200 it probably won't leak even if there is stress evidence of damage. So I would not use no sign of a leak as evidence of no damage.
The most vulnerable area of the hull is at the aft end of the keel. A strike on the lower leading edge levers the aft edge up. High aspect fins are notorious for fracturing this area. Unless a fracture goes right the way through, it won't leak, but it will be weakened. If you can't see anything now, you are probably OK for the time being, but have that area checked very well at your next haulout.