I could never ask to borrow anyone else's boat. If offered, maybe take them up on it but not just ask to borrow.
I would be too stressed out to enjoy the lake that day anyway thinking that I would ruin the relationship if anything happened.

In-laws and my family tried joint boat ownership for 4 years, but I got tired of solely maintaining, storing, cleaning, and "asking permission" for something I was co-owner of. Never again and almost burnt a bridge. It was not a wake boat anyway and never had the same fun as we do now.