Has anyone used these guys for an Australian timber yacht and have any comments on their experience?
(That is, good or bad comments on the insurer).

Have 50yo fibreglass yacht on a swing mooring. Third party with New Wave gives you access to Marinas .
Good communication/efficient,but no claims,yet have certificate of currency !
Few options available - only found one other - but maybe try a broker ?
May be different if you have a positive recent survey,and want full comprehensive but = $

I use them too for 3rd party.

I use them for my 40 yo fibreglass yacht full comprehensive. Easy to deal with but no claims yet

I know its not exactly answering the question but if you are looking for an insurer that will insure a boat on a swing mooring and 3rd party Ive been using Pantaenius and found them very helpful.