I always buy RBC (cancellation and interuption)and have had to use it 2 times. One time, we had to use the interuption clause because a snow storm in Toronto delayed our arrival there and resulted in our missing the connection so we missed the ship's departure. We had to make our way to Grand Cayman and get on the ship there, RBC paid all expenses that were not covered by the airline.
The second time we used it was for cancellation because I broke my leg, required surgery and was in a wheel chair. We got a full refund. You do need to read the details but death, illness, accidents of family members are valid reasons to cancel. Obviously, I never travel without it now although I used to. Travelling in February from Canada, it's a must.
Have a great time,