I read about the catamaran tour on the locogringo site. The bay that this place is in is called Xaac bay. Google it and see for yourself.
As for ruin tours, just take a collectivo (local transportation) to the ruins for $2.00 and you can check the place out at your leisure. Why pay extra for a tour when they don't do anything you cant do on your own. Just tell the driver you want the Tulum ruins and he'll drop you off across the street from the ruins. Chictchen Itza is a different story. That's a tiring 3 hour bus ride EACH WAY. Up to you though. If you book tours of any kind through your resort, know that it's gonna cost a little more than if, say, you booked at Tulum ruins (there is an open air market there where you can book anything, negotiated) They still pick you up and drop you off at your resort. Remember, it's a competetive industry and they will talk lower prices.
As for the locogringo site, google "mayan riviera aerial tour" and the locogringo should be the first one. Scroll down to the airplane icon, click on it and away you go. Click the double arrows, not the single ones and head to akumal. Xaac bay is just north of the town. Click on the word "Xaac Bay" and you'll see some photos of when it was a secluded spot.