I have a Gold Credit Card with Lloyds and it comes with free Travel Insurance for the year. Card costs nothing but you do need a postive balance in the Bank! I think you have to have £1000 in the account but cant remember the details as been doing it for a few years now. Hope this helps.
Noble Marine have a link to a travel insurance policy which offers all the usual benefits of a travel insurance policy, plus extensions to include offshore sailing and racing. See Travel insurance for sailors