We've eaten at a Mexican restaurant called La Mission. It's on the main street by the ocean where the cruise ships dock...Av Rafael E Melgero....up north by the ferry dock (that goes to the mainland). If you get off the ship and turn left...walking up the street where all of the shops are, it's almost to the end of the street near the Plaza San Miguel Shops.
We've walked up there, it isn't that far, but one time we grabbed a taxi back because it was very close to all-aboard time.