Little story (non boat related).
Early in our marriage we owned a little Mini Cooper. One day we had a flat tire (tyre), I even remember it was the front right wheel!
I got out the lug wrench and started to remove the first nut. It wouldn't budge. I tried and tried and nothing. So finally I put the wrench on parallel to the ground and jumped on it. Yep - it snapped the bolt.
And in the half second after it happened, maybe even before the nut and bolt hit the road, I realized I was tightening it.
The other nuts came off easily!
We must have driven for years with one bolt missing on that wheel!