Water in Keel - CP 25

[Restharrow]

I'm seeking advise on a potential bilge/keel repair.  At the bottom of the bilge in the interior on my CP25, I've noticed a gap  along the port side between the bottom of the bilge and the side wall.  It's about an inch wide and maybe 2-3 feet long, don't know how deep it is yet.  Maybe about an inch before I hit dirt, sand, or keel filling material?  There's NO evidence of exterior damage, but if water remained there over the winder I'm sure it froze and expanded. Any suggestions, advice about what I'm dealing with?  I'm thinking clean out what I can and fill the gap with epoxy.
I decided to bite the bullet yesterday and drilled a small hole near the bottom of the keel. A small amount of water did leak out, so now it's dry out time, then repair. I also degreased the bilge yesterday - looks great.

Update 7-29-16:  I was able to  fill the gap with rolled up fiberglass tape impregnated with epoxy.  Took two applications and some epoxy ran into the aft portion of the bilge and puddled - which in my opinion was a good thing.  Not sure why the bilge slopes aft into a small pocket to collect water.  In any event after the bilge gap was repaired, I covered the entire bilge bottom with a lap up the sides of about an inch with a piece of fiberglass and impregnated it with epoxy.  When all was dry I repainted the bilge.  No more issues!!  Oh and I plugged the hole I drilled in the keel.
Thanks
Steve CP 25
Lake Champlain and Coast of Maine