Anything that involves being captive with other people sounds more like where you go if you are bad.
I like to go out, do/explore things on my own, and avoid anything with the name "group" like the plague.
And I don't think $70 per person per night is all that cheap either.
Yankee thread has taken a cruising twist...personally I think a cruise is alright but certainly arrange all the shore excursions yourself as opposed to doing it through the cruise line. You will save 25-40% off the cruise's price to go on exactly the same excursion (that % is the cruise line's cut from which you receive ZERO additional benefit), in addition to the fact that doing it on your own puts you on your own schedule - just make sure you leave yourself enough time to get back to the ship! If your cruise operated tour runs late, they hold the boat. But if you yourself are late, have fun trying to get to the ship at the next port. A typical cruise tour will look like this: Be on the pier no later than 8:15. Then after you "check in" for your tour, sit around for 30min until all 40 of you board a bus. Then drive an hour. Pause for 45min while everyone looks at gift shop/bathrooms. Then 2/3 hour tour activity. Then repeat a 45min bus loading operation along with a 30min gift shop/bathroom break (bear in mind that the tour operators and cruise ships have extra incentives to drop you off at the gift shops - they usually get a cut of the sales)...what the tour cruise does in 6 hours, a well planned traveler can do in half the time for half the price