Suggestion: "Booking private tours beforehand can be cheaper than taking the boat's tours" (section 5, number 5 on the infographic if you want to look at it)
Honestly, I'm not sure if this is referring to tours before and after the cruise itself or tours in the ports of call during the cruise. Here are a few thoughts on all of the above!
If you're talking about a tour before or after the cruise itself, this may be a true statement, and is generally going to be more applicable in the cases of cruises like Alaska or Europe/Mediterranean where cruise-tours are popular. Because I've personally never done one of these, I can't speak to it. Jeff has done the cruise-tour thing in Alaska. On the whole, he really enjoyed getting to see different areas he wouldn't have gotten to see otherwise, but there were definitely down sides, not least of which was the cost. However, there is an element of the convenience factor. You may can find a cheaper tour after you get off the boat, but you may be responsible for getting yourself to the start of that tour, taking your luggage, and other things that are worth considering. Do you have to get a cab? Is there a "missing meal" you'll be responsible for? Just factoring the cost of those two things can make a big difference in what is cheaper!
"Home Port" Excursions
If you're talking about single day "home port" excursions, chances are that you're going to be doing a lot of paying for convenience. I'm going to use the specific example of an excursion some of our family members are considering for our next cruise - going to Kennedy Space Center for the day after we get off the ship because the flight home won't be until 6pm.
- It's something to with yourself between getting off the boat and getting on a plane
- Carnival will get you to the space center and then back to the airport (this may or may not be a major cost contributor)
- Carnival takes care of your luggage - not just getting it off the boat and onto the bus, but also checked to your airline. (You can do this without booking a tour/excursion but there is a cost for it!)
- It's expensive (more than twice the cost of simply buying the tickets on your own, but may even out depending on transportation costs)
- You're stuck on their schedule
- Carry-on luggage is pretty much impossible unless you want to carry it around all day, and you have to pack up everything to be checked and have it outside your room the night before. (In my mind, all I can think is that I'll have to sleep naked and then toss my toothbrush in the morning!)
As you can see, there are some important things to consider both ways. For some people, the cost is worth it. For others, it may be cheaper (or simply worth the price difference) to do something on your own for the day. Another option (and one that is most appealing to me at this point) is to plan to stay in a hotel that night and go home the next day. Even if you can't check in first thing, many will let you leave your luggage and then you can do something cheap or free (like going to the beach) and then take a flight the next day.
Port of Call Excursions
I suppose it's always possible to make your own arrangements before you leave home, but this one is kind of an odd situation. Some people swear that the best time to take tours would be on your first visit to a new place. Others prefer to explore on their own during the first trip and then see what is interesting and book tours during later visits. If you want to make your own arrangements, you'd probably have an easier time doing this if you're in the second group. However, if you do this, it would definitely be worth knowing what kind of cancellation policy or insurance you have, but don't assume it exists. This is one area where, in my experience, excursions booked through the ship or cruise line have an advantage. I have had an excursion (snorkeling) cancelled because the ocean was too rough since it had been stormy. We could still use part of what had been purchased (going to a beach park) but we did got a refund on the cancelled part.
Now, that's not to say you can't make your own arrangements on your first visit to a new port. You would just have to kind of fly by the seat of your pants and look for something as you get off the boat in the port and have the cash on hand to pay for it. There is a little bit of risk in doing this because you are going to be on your own and responsible for getting yourself back on the boat in time to leave! But, you don't have the risk of losing out on something because of inclement weather or just not feeling like doing it because you haven't committed to anything!
I would say to just think logically about your own situation and what you think is right for you and your vacation. My personal preference is often to pay for convenience and book things ahead of time so that I can budget for it and plan for it. Often times I can pre-pay for it (sometimes getting a better rate) and it's one less thing to have to worry about having cash for. I know plenty of people who would rather haggle and wait for the last minute deals, but that also runs the risk that you'll end up having to pay more because of high demand and do a lot more sitting and waiting.