insuremy trip dot com, will show you all ins carriers with their individual quotes thereby giving you options.
Most important, generally speaking are the
EXclusions....Like pre-existant and what their "look back" date is. I have used them, they are very reputable, and competitive, good prices. So, you can do that yourself, likely get Better, cheaper coverage. A cruise is expensive, so I think its a smart investment. No need to go overboard, but be SURE to meet the requirements, by that I mean, if they say insure the Whole trip, do that, don't cut yourself short because in event of having to get paid you will need to show proof. We had to use ins once and we got back Thousands! Its important to know what you actually need (in other words, if your FIL was sick (heaven forbid) and you had to cancel they look back XXX days and say, oh, he was sick a while ago, that is PRE existent, thus NO coverage, so THAT is something that is important to note, especially if there are any sick people that you may want to be covered for. Hope this helped! Good Luck, its actually rather simple, and can all be done online. Usually the DIRECT coverage (FYI: like thru Carnival or Disney for that matter) does NOT cover pre-existent!
ALWAYS check the exclusions!!

*oops, meant to add, you can get ins up to day of travel BUT you will pay more.....