big bite outta my keel
Like they said, its not the greatest thing to happen, but depending on how bad it hit, how big a chunk was taken out, how long it was in the water after is what really matters whether the water has migrated past the spot of impact.
The very first thing I would do is haul the boat and grind the fiberglass away from whole area of impact. Who knows, maybe the iron keel to fiberglass shell had made a good bond at that area and the water intrusion is limited to that one particular spot? If you are lucky & it is isolated you can let it sit and fix it, if not you''ll have to do what everyone else suggested.
I might add that I would think about also forcing hot air (like a heatgun with a high volme of air?) into the dilled holes enough so that you can possible feel or see air coming out your weep holes. Leave that on as long as possible and you might be able to get most all the moisture out. Seal the thing back up well and go sailing. I think if it was a good qualitysolid pice of iron you''d be ok for a long time. Even though I am no fan of iron keels, the reason I say that is because talking to some people that do have exposed iron keels that are not coated claim that the actual loss of iron is negligible in terms of overall mass. They are a mess though with all the rusting and painting they have to do every year (or not paint like I know one guy does). He just doesn''t care what it looks like, but the whole keel looks like it has rust "pot-marks"