Local snorkeling is often good during the dry winter season, especially at Playa Tenacatita , off Highway 200, several miles north. Snorkel and scuba tours and instruction are available in Barra de Navidad  through Sea to Sierra Outdoor Adventures (Av. Veracruz 204, tel. 315/355-5790, www.seatosierra.com ), across from the town jardín. Although Sea to Sierra has no scuba instructor, they partner with the professional PADI-trained instructors of Nautimar (tel. 315/331-0500) dive shop at the Hotel Grand Bay.
The best-organized and most professional regional dive shop is Underworld Scuba (P.O. Box 295, Santiago, Colima 28860, tel./fax 314/333-0642 or 314/333-3678, Carlos’s cell 044-314/358-0327, Susan’s cell 044-314/358-5042, www.divemanzanillo.com  or www.gomanzanillo.com/scubamex ), run by Manzanillo-based Susan Dearing, and her partner, NAUI-certified instructor Carlos Cuellar.