Having been to the Galapagos for two weeks, I can tell you it was amazing experience. Before doing this, I did some research on best ways to go about seeing and the cruise seemed best as they offer day trips. The cruise will you the opportunity to see all the Galapagos islands such as Cristobal, Santa Cruz and Isabella.
Oh really, we are also going there on coming august month. Hope we can have great experience there as like you.
cruise ship vs small boat The options are basically: 1) take a cruise 2) visit the islands from a hotel base on land. If you are prone to seasickness you are better off staying on land, though if you plan to take day trips from Santa Cruz Island, be aware that you will be doing so on a very small boat. A cruise ship would much more stable in rough seas.
I'd definitely recommend taking a cruise. This way you don't have to organize day trips for every place you want to visit. And you definitely want to hit different places to see the Marine Iguanas, Tortoise, Blue Footed Boobys and much more. Being on a cruise will also give you much more opportunities to go snorkeling!