How Did This Happen??

I had noticed an abnormal amount of water in the bilge since Labor Day...water up to the top of the bilge pump after wakeboarding for an hour. Didn't think too much of it and planned on removing the RR seat, back panel, etc. when I pulled it for the winter to investigate...figured airguide hose or exhaust or maybe even platform bolts. Needless to say I was pretty shocked when I pulled it out of the water and took a look underneath when it was on the trailer. Big question is what caused this? This boat lives up north on a lift so it gets used roughly every other weekend late april - early october. When it's being used it has ~1000lbs in ballast and the lift isn't all the way up so the boat is partially in the water. The hole is also roughly at the end of the boat lift bunk and right where the secondary stringer "cuts in" at the back of the boat. I figure boat lift bunk corner + ballast + boat bouncing from waves all summer or maybe just one big wave? what do you guys think? Luckily I found a guy fairly close (~45 minute drive) with 40 years experience repairing fiberglass who says "no big deal"...last photo is the boat at his shop...it was a nice day...

definitely didn't hit anything

Did your stringer crack and pull-up the exterior hull into the bilge

Those close ups are interesting but I can’t make heads or tails of them without a little context (size and location). Can you take more pics from inside and outside zoomed out a bit?

One theory...

I’ve seen boats on lift bunk brackets that barely made a scratch.

Something very strange here

no, i think it's from the boat lift as i mentioned above. the "hole" lines up about with the end of the boat lift bunk which, with this lift, is like the corner of a 2 X 4...so it could generate a large point load under certain conditions (ballasted boat + waves). also, it wasn't really a hole...that photo is after i poked my finger in there. it looked to me like it had been repeatedly flexed in that area and the gel cracked away and the resin cracked allowing water in.  that seems like the most reasonable explanation to me, just wanted to see your all's ideas.  no shrapnel on the inside. 

I’ve also got a Hewitt cantilever lift. Works fine, but in low water I managed to scrape the hull on the bunk while backing off the lift. The corners of the bunks are certainly sharp enough to damage fiberglass. I think your theory is correct. If you’re gonna have it on a lift, the lift needs to be raised until the boat is solidly planted on the bunks.

NICE. Good time to grease the rudder!