Hey ladies, my gf's and I did this a few weeks ago. Yes we booked it at the resort but it was throught Coco tours which I would not at all reccommend. We felt a little mislead. It took about 1hr 45 minutes to get to a speed boat to take us to the sand bar where you swim and find starfish. The starfish are not as easily found as you would hope. Every now and then someone would find one and everyone would gather around for pics. Well our speed boat kept breaking down and we had to keep getting jump started by other boats batteries. Once we made it to Saona Island it was gorgeous. But you really get hassled about buying jewelry, coconuts and coconut oil, and getting massages. As long as you keep saying no and dont mind the constant harassment you are fine. The water is an amazing color and so is the sand. The buffett was not very good and the "open bar" included rum punch which they ran out of , rum and coke, and beer. The catamaran ride back was very nice and relaxing. If I remember correctly it was about $75 per person. Hope this helps let me know if you have other questions.