In the UK we have to have travel insurance as part of the 'right of passage' onto planes or ships, though oddly not on international trains or ferries etc.
Fortunately there are a lot of quality independent providers, and that keeps the price down for most people, and when you consider the cost of medical treatment, or worse, repatriation (especially if airlifted off a ship) you can soon run up bills of several thousand.
We have had a couple of experiences of claims, once for ourselves when we had to cancel a cruise on a Renaissance ship, and the other for onboard treatment of my gran after she injured her leg whilst on a cruise. Both times the companies paid out without any hesitation.
So, for us it's a necessary evil, but one that is worth it's weight in gold if you have to claim.
Alan & Katrina
Last Cruise: Royal Princess August 2015
Next: P&O Oriana October 2015
Then: Queen Victoria January 2016
Golden, Grand(2), Caribbean, Royal, Sea(4+1 aborted)
Adonia(4+2), Arcadia, Artemis(2), Aurora(5), Azura(2), Britannia, Oceana(3), Oriana(11), Ventura(2), Victoria(5)
QM2(2), QE2(9), QV(6), QE, Caronia(2), Minerva, Minerva II, Fred.Olsen(8), NCL Jade, =X= Eclipse, HAL Ryndam, Aza.Journey