Whenever I travel overseas I purchase extra travel health insurance. I go to some remote places with typically bad health care facilities so I like to think that I could be air lifted out if needed.
We always buy it when we go on cruises. Yes, the medical coverage is helpful, but for cruises it also protects you if you miss the ship due to flight delays/weather. I think that we have always used insuremytrip.com to find the best price/coverage.