skabeeb, one of the things you will find out about IMIS is that they aren't shy about pointing out differences in policies. Sometimes, they can't compete with price. Many other times, they'll be able to show you specific differences and gaps in coverage.
You really want to see an actual policy when comparing insurances, and (surprise!) the insurers never want to send one out until after you've contracted with them.
Policies may vary in terms of replacement value versus depreciated value versus agreed or named value. In terms of environmental damage coverage, wreck
removal fees, exclusions, sailing areas...The quote you get up front is pretty much like putting an ad in the paper "Wanted, spouse, age 32, brown hair, brown eyes". You could get three dozen replies that all meet the criteria--but do you think you'd want to marry one with
just that information? <G>