Sounds like we did this same trip several years ago. My husband and I are in our early 50's, get around very well and could probably do trips on our own. However, and especially if this is your first trip to these ports, I highly recommend taking the ship's tours. We usually sign up for them before we leave, especially if there are trips we don't want to get closed out of. Yes, the trips may be a little expensive, but they are usually well organized, you have a guide with you explaining, and in most instances, the distance from the dock to the points of interest is rather far, so just the ride to and from the ship accounts for a lot. I seem to remember several "like" trips offered at some of the destinations, some more walking and active, and others more bus rides around with less activity required. If a tour you are looking at says, "uneven pavement, steps, lots of walking, should be in relatively good shape"; please keep this in mind or you'll find youself missing out on many highlights of that tour. Please let me know if you are interested in any specific destinations and/or tours, I'd be happy to help.