Our family (kids 5 and 9) will want to take a day trip boat tour from Cartagena to the Rosario Islands. We'd like to snorkel, we'd like to NOT deal with Playa Blanca (happy to do a different beach), but we WOULD like to go to the aquarium. If there were something like the Diving Planet http://www.divingplanet.org/en/daily-fun-dives.html?var=snorquel
trip with a stop at the aquarium, that would be ideal, but we don't need as much snorkeling/diving expertise as they have.
We'd also prefer to not rent our own boat since there are only 4 of us and that seems REALLY expensive.
What can people recommend? Thanks.