Like Cozcharlie, I would consider Residents Reef for VRBO (next to Sabor, Secrets and Dreams Resorts) and picking a good dive Op. All of the good dive Ops willl pick you up at the Sabor pier (There may be a small fee to use pier, like $2). It is a short ride (15 min in a 6 pac, barly enough time to suite up) to the southern reefs and the second dive could be just in front (5 min ride back). You can also book at Sabor, Secrets or Dreams resorts since they are all together.