I logged in this afternoon and there were 128 new posts. After deleting the
OT's there were 24. This ratio varies here but 5:1 isn't atypical.

There are other boating newsgroups and in them I don't see any OT posts so
it's not a necessary part of usenet.

I remember other other non-boating groups in the past that somehow became a
target of spammers which killed the groups. OT is spam and regardless of the
specific ratio on a given day it constantly outnumbers on-topic posts.

The "did not/did too" bickering and name calling leaks into boating related
threads, you just have to look at the "trailer tires" thread to see an
example of how the bile spreads.

The mean spirited post by the guy using the remailer should have been
ignored. It should have been left to die alone with no replies but instead
it turns into a hot thread. That speaks volumes.

Is it unpleasant enough to drive people away? Obviously it is.

It can only be stopped by those who post the OT. It can only be stopped if
they stop posting OT.

It's pretty simple.