Will always buy insurance!
I think it is a good idea to buy insurance that is not the cruiselines. I have used Travelex, Access America and CSA.
What if your parents get sick, your children have an accident and you have to fly home, you break your leg in a small Caribbean country and your health insurance won't cover you, etc ......How would you like to pay for air evacuation on your own?
It is worth it!