I fell and broke an arm last year on a European Carnival cruise, ended up going to the ER in Belgium The cruise lined did not charge me anything for setting the break and a splint as I fell due to a trip hazard, the Belgian hospital only charged 156 euro for x/ray and another splint.
I had AIG insurance that did reimburse me for both the ER and the cab rides back and forth but it took them about 6 months to finally pay.
For my next cruise I chose the NCL insurance, with the low deposit, I feel like I am self insured on that and we do have Medjet ins as well.