Ashley,
Organisers of events are becoming more sensitive to possible claims against them if people are injured – all part of the ‘Elf & Safety culture nowadays.
Obviously, if you are running potentally dangerous models such as steam boats, hydroplanes or fast electrics etc. it makes sense to protect yourself against third party claims. People who run scale models often claim they don’t need it but what if somebody leans over your model and the mast pokes their eye out? In days gone by they would have accepted it was theit fault but in today’s blame culture you are more than likely to have a claim made against you or the organisers.
Clubs often have their own insurance but this can vary and sometimes only covers you for your own events or sailing on your home water. Insurance is one of the reasons I keep up my MPBA membership as this gives pretty well universal coverage. I think the MYA scheme offers similar benefits.
Colin