Does extended mean more or less than three months?
Are you looking for cancellation and travel interruption insurance of just medical evacuation and/or medical?
www.insuremytrip.com is a great site to compare different policies. We have been using CSA for a while; they have always been reasonably priced and have paid off on a couple of small claims on last two cruises in a timely manner.
I just found out, though, that my TA is able to get cheaper "group" rates at CSA than are available on insuremytrip.com. So, check with your TA after you have done initial research.
BTW, if you are under 75 and are just looking at medical evacuation, I would recommend a policy with medjet.
"The test of a first rate intelligence is the ability to hold two opposed ideas in the mind at the same time and still retain the ability to function."
F Scott Fitzgerald
Silversea Silver Explorer (23nts) - Kangerlussuaq, Greenland - Nome, Alaska - Aug 14
Seven Seas Voyager (30nts) - Dubai - Cape Town - Nov 14