This may sound like super odd advice, but I was so thankful the cruise line gave us a heads up before we disembarked at Cuba. Sadly most charter buses (cruise excursions, included) and restaurants in Cuba did not have toilet paper. Also, many tourist stops and restaurants charged a dollar for access to a bathroom. Best to be prepared and carry a roll with you!
The best hop on hop off bus seats aren’t in the front row of the top. The glass causes reflections on your pictures and will leave you disappointed. Instead sit half way back on the top. Also, pay attention to the location of the top sights as that may help you decide which side to sit on. Of course, we like to move back and forth between the sides so hopefully you can do that, too, on a less full bus.
Today Rebecca is enjoying Sydney from a hop on hop off!
Hop on hop off buses or boats are a good way to see a lot quickly if you are short on time. It is also a good way to initially orient yourself to a city you will be spending a few days in.