There is the Playa Bonita beach just on the north edge of Limon. That's the only one I personally have been to. We had a taxi taking us all over town when we were there this month. I won't say that it's the most perfect beach but I would definitely go there. It's a public beach and you probably would see as many locals as tourists there, plus a few vendors trying to get you to buy their stuff/junk. Very nice and wide sand beach area with rugged coral and rock to the left and right of the beach. Quite picturesque. There is also a cafe/bar right on the beach as well. We didn't take the time to try it out but it looked like a interesting spot. If you would like to see where the beach is in relation to the pier, take a peek at the map at:
<http://www.costaricamap-online.com/php/map22/map2201.php>
the map enlarges when you click on it. The ships usually dock in the Port of Limon at the piers alongside the peninsula. You'll see Bonita Beach (Playa Bonita) directly to the north. If it's too rough at the port, cruise ships sometime will dock at the freighter port of Moin, just up the coast.
