Quite a few years ago a buddy and I were following each other most of the day out fishing, we ran further out in the salt then usually one day, and a storm was coming on fast so we figured we'd best get back to the dock or at least back to creek where we launched from.
We were going all out trying to stay ahead of the storm, already getting pelted with hail as we turned and headed up river. About half way up the river there's a few areas that look like open water but are not, the main river winds around to the left, and the straight away 'open' water is only a few inches deep at low tide. I was following my buddy who was running an older 18ft Starcraft with an old 65hp electric shift motor, I had a newer modified V hull bass boat with a newer 60hp on it. I was lighter and faster so I let him set the pace.
As we rounded the first bend in the river I saw his boat do sort of a hop on the water and we saw the prop come out of the water for bit then he drifted to stop still trying to figure out why he had no forward momentum. But hat time it was pouring rain and starting to really hail. He tried to pull the motor up but it wouldn't move. He also said the fuel tank, which sat under the back of the boat was now hitting the bottom of the splash tray. I pulled up, tied off to his boat and just towed him the rest of the way.
The rain had either passed or we got out from under the storm as we got back to the ramp. He gets his truck and trailer, and one of the guys with us jumped out and led his boat to the trailer figuring that it may have an issue getting up the ramp since the motor wouldn't tilt.
As he pulled the boat up the ramp we could see how bad it was. His prop was gone, which at first I figured it wasn't such a big deal. The skeg was still intact.
I got my truck, loaded my boat and walked over to see about getting his motor up so he could tow it home.
It too a second but I did a double take and realized not only was the prop gone, the shaft was gone too, leaving a hole where the shave sued to be. I could stick my finger through the seal and feel that the shaft was there but broke off just beyond the bearing.
Closer inspection showed that the tilt pin, (manual tilt) was bent. It bent so much so that the release lever didn't have the leverage to disengage the pawls. A few taps with the hammer and it was free and he was able to strap it in the up position
With the motor up, and boat done draining we got a good look at the bottom of the boat and the bottom was dented upward about a foot on mostly on the right side leaving the imprint of the three rear transom gusset braces showing through the bottom of the hull. It wasn't until he went and found a parts motor for a good used lower unit that he realized that the whole motor bracket was cracked at the throat of both clamps. What ever he hit made first contact about 3ft forward of the transom just off to the right of dead center.
At that point he just walked away and went an found another boat.
A couple of us went back the next morning in my boat at low tide to see if we could see what he hit, but there was nothing there, then as we went further down stream we found an 8ft log that had washed up against someone's private dock with a prop embedded in it and a massive chunk missing.
The log was a foot in diameter and super old looking when we tied onto to it figuring we'd bring him the souvenir we could barely move with it in tow being that it floated beneath the surface, so we beached the log and pounded the prop and bent prop shaft out of the wood and went home. It hit so hard that the one prop blade was half torn off the hub, but the rest were undamaged. The shaft though looked like it had already been cracked being discolored about half way through the break. It also had a bit of twist in it just beyond the splines.
He sold the boat no clue whether the buyer fixed it or not but the motor was just parts. A closer look at the drive shaft also showed the four splines were twisted nearly 1/4 turn.
In later years, others have hit logs like that, there. Many year ago it was known for stumps in that area where they had cleared out trees and moved the river over a few thousand feet to build a bridge that never happened way back in the 1920's or so. After years of dredging most of the stumps are gone but logs even telephone poles are a real issue. I've bumped over a few but never at high speed like that. (He was probably doing about 35 or so when he hit that log.
His next boat was glass, which turned out to be a bad choice, about four years later he hit a log in another river that was stuck in the mud. He was passing someone outside the marked channel and hit the end of the log at 30mph or more. It stuck the boat like a spear blowing a 12" hole in the bottom in about 3ft of water. He was lucky that the log kept the boat from sinking and it just sat there hanging on that log.
It took two of use and two other boats to go get that one for him. He never bought another boat after that.