Stephen
For many years covering ownership of a Parker 21, Parker 275 and now a 325 I have used a 'Yachtmaster Insurance Services' of Woodbridge. You can contact them on 01394 615755 or bt e-mail on enquiries AT yachtmasterinsurance.co.uk. They used to be based in Boston and many new Parker owners went to them.
A point of interest - one year they chose for me insurance with Navigators & General. As N&A were recommended by the SSA, I knew they would give a contribution to the Association if I went with them direct. I contacted N&A them saying I was a member of the SSA and to my amazement, they quoted me about £40 more than I was quoted through the above broker.
I went with the broker.
Regards
Don
Don Harvey