I'm not sure that is wholly correct - I have renewed over the phone with GJW, but dinghy claims are now online only.
I have both a yacht and dinghies insured through GJW and find them best on price.
I have always used what was St Margarets, now Haven, for dinghies and cruisers; they seem a good outfit, always helpful and when I shopped around a while ago they were still competetive.
Also I have seen GJW respond very well when friends had claims, if their conditions suit as mentioned above.
I've never had cause to claim but judging by their communications when responding to queries, I'd recommend Yachting24.com .
Hopefully I'll never have cause to regret that recommendation.