Manipulation? Hell no! There's no manipulation implied at all.

True guilt should come naturally ;-)

If I were to damage a friends property, I'd feel really, really bad.
Thus, I'm loathe to borrow (or even rent) from friends (as has been
mentioned previously in this thread).

Further, having lent to a friend, I'd feel badly making them pay for an
expensive repair on an old or used boat.

Neither a borrower nor a lender be if you value your friendships... go
to a legitimate rental place and pay the market price... that'll keep
you guilt free!