Anybody with a boat should have *at least* $1mm liability umbrella.

I disagree. I understand your point, but putting a million dollar
liability policy on a '89 Aquasport 23 seems a little outrageous and
it is being viewed as such by those who have older, serviceable boats.

It's not about damage TO your boat, it's about damage BECAUSE OF your boat.
It doesn't take much to run up a pretty big bill when you take ALL of it
into account. Damage to another boat can be a lot, but damage to docks and
injuries to people can be a LOT more.

Call your homeowners insurance company, or your automobile. Ask them what
an umbrella liability policy will cost you. Our was dirt cheap, something
like $175/year. Given the potential loss risk that's a bargain.

Can't be for a smaller, older boat - the cost has to be prohibitive in
terms of boat value.
For something like your boat, I can understand it. For our
hypothetical '89 Aquasport, it isn't cost effective.

Check first, post second. Run the actual numbers, you may be surprised.

Which is not to say that I don't carry that much insurance I hasten to
add - I do just because of what I do. But if I didn't, I'd be hard
pressed to justify it just because a marina required it.

Then move to another marina, I'm sure the other boaters in the marina will
breathe a sigh of relief.