We just got back from our trip to Ocho Rios and the Caymans and I highly suggest that you do book some sort of an excursion in Ocho Rios. I wish we had. We no more than got off the ship and walked right back in. The locals were ridiculous and in our face. One man got in my husbands face and my husband could smell his breath and the guy would not back off. We should NOT have tried to experience it on our own. I highly suggest booking an excursion.
In the Caymans we got off the tender and walked to the shopping area and then took a taxi to 7 mile beach and LOVED IT! It was a good time but wish I had went to Stingray City. Now looking back, I would have loved to have experienced that.