Yet another thing that you must educate yourself about when first starting to cruise is how to select the right excursion. These side trips vary widely in exertion and focus. It is really important to critically evaluate the specifics associated with the excursions you are interested in taking. Reading the marketing blurb is a start, but take the time to read up about your destination from another source. The more you know, the more educated a choice you will be able to make.
Cruise lines strongly encourage you to book excursions through them. There are definite benefits to that including transportation for excursions picks you up and drops you off at the ship (or in the terminal). Perhaps the most important thing to keep in mind is that if an excursion you book through the cruise line runs late or breaks down, the ship will not leave port without you!
I remember one excursion years ago. My husband and I decided a bike tour in St. Lucia would be fun. It was described as moderate exertion through "gentle rolling hills". We rode our bikes a few times a week and felt confident this would work for us. The reality was that inclines were well beyond gentle or rolling. One guest had an asthmatic episode and ended up on the bus for the remainder of the trek.
Cruiseline.com provides some guidance on selecting excursions so you can be prepared to have a better time, http://cruiseline.com/advice/before-you-cruise/what-to-know/9-things-you-need-to-know-before-booking-a-shore-excursion
Does anyone else have a lesson learned taking port excursions?