Having been on a cane for 35 years, starting out using it only outside my home, I discovered that I would leave it behind when I didn't need it as much as I eventually did (for ALL my walking). I had to remind myself to check for my cane every time I stood up from a seat so I didn't leave it behind. You might want to practice that before your cruise, and also tape a luggage tag with your cabin number on it in case you do leave it behind at some point.
Also, another "up vote" for the reassurance that you won't need to worry about the rubber tip wearing down for a long, long time.
By the way, one of my happiest discoveries was fashionable canes dot com . . . As long as I need a cane, I may as well choose a great looking one (or six. No kidding).