From San Miguel de Cozumel, follow Caratera Parimetral Sur or Caratera Costera Sur towards Zona Hotelera Sur.  At a point when these two roads re-connect (approx. 10 mi/16 km), look on the right for the clearly marked entrance to Residencias Reef.  Geolocation: 20.403481 -87.015159

https://www.youtube.com/watch?v=Sgscub792FY