Me and my family (6 members) booked athe Isla Tortuga tour from Montezuma earlier this month. We found the staff to be very pleasant and helpful; from booking (online, and follow up questions) to the boat captain and mates.
Our tour included a hour boat ride to the islands, snorkling, lunch, play time, then a boat ride back to Montezuma.
The staff on the boat were very friendly; I've never launched a boat from the beach before, but the staff were helpful to ensure we all boarded safely, offered everyone a drink of choice (great beer by the way!), and we were on our way.
While snorkling, our guide spent a lot of time pointing out fish and other sealife to whomever was swimming close by, and would make sure everyone had an opportunity to see something unique (like puffer fish, starfish, eels, sharks, etc.); things snorklers might have missed otherwise.
There was plenty of fresh fruit on board (pineapple and watermelon) and at lunch (more melon and coconuts), and drink as well. After lunch (which was good, but nothing to write home about) we had plenty of time to take it easy in the water around the beach before boarding the boat for the ride back.
I found the tour to be interesting, and fun. Zuma seems to be a first-class outfit!
I don't know if it was intended or not, but we booked online and received an automatic 10% discount off the advertised rate.