If your in Vic, try
tudorinsurance.com.au/ They do older boats, and swing moorings.
Their rep came onsite to our club, sussed out the local area, and then did a club members policy rate.
Most were just after '3rd party', but I put my cat through for fully comp,and social racing as they were QBE agents.
No survey needed, boat just has to be looked after and you supply some decent photos to prove it.
The only thing they won't touch at all is ferro.
No allegiance, just happy customer.
Usually I'd tar most insurance companies with the same brush, but at least this broker gives us a bit of a chance instead of flat out no for old boats/swing moorings.