I had chronic liver disease for more than 30 years before my transplant. I've found that insurers, at least during those years and the insurers I was dealing with, waived the pre-existing condition clauses of their contracts if the insurance was purchased at the time the trip was booked, at the time of the down payment. It's been a couple of years since I bought a travel insurance policy, but I'm guessing that is still true. I'm sure I did diligence when I booked my Boston to Boston journey but I'm going to go back and read that policy because I'm getting a bit forgetful in my old age. And yes, we're going to spend 3 days in Boston before our tour starts; I'm collecting restaurant reviews in case you have any recommendations. Your cruise sounds so relaxing and you'll be able to defrost!