Cave diving on Andros

• Blue holes: Andros has 178 inland and at least 50 ocean blue holes (Wikipedia; Caribbean Beat counts 164 and 110). Many are layered: fresh water on top, salt water below, often with H₂S at the halocline (Stargate ~15 m, Guardian ~27 m) and sometimes a bacterial layer (Stafford Creek at 6 m, the Black Hole at 17.8 m). The fresh top layer is often murky (3–9 m visibility) from decaying plants; below the halocline >30 m. • Rules: Blue Holes National Park (BNT, since 2002, 40,000 acres, 22 inland blue holes; Captain Bill's Blue Hole is a free swimming spot with a jump platform and stairs; BNT guides by arrangement). The AMMC protects all blue holes and caves: research needs a Bahamian research permit plus AMMC approval. Lucayan remains were found in Stargate and Sanctuary Blue Hole — never touch bones. The Black Hole may only be dived for science. • Operators: Small Hope Bay Lodge (Central Andros, since 1960; +1 855 841 6966, info@smallhope.com): boat at 9:00 and 14:00, 1 tank $125, 2 tanks $150, 'Ocean Blue Hole' and the Diana's Dungeons cavern dives, nitrox $15; in 2010–2011 the lodge guided dives in Guardian and flew divers to Stargate — ask whether that is still possible. Andros Diving at Andros Beach Club (Kemp's Bay, South Andros; +1 242 554 0411 WhatsApp): inland blue holes including Stargate $190, ocean blue holes, 2-tank boat dive $220, max. 6 divers per boat. Bahamas Underground (Abaco) runs trips to Andros. Andros tourist office: +1 242 368 2286. • Tides: ocean blue holes 'breathe' with the tide — plan around slack water with your guide. Conch Sound has a net outflow (1.57 m³/s measured in 1981). • Getting there: flights from Nassau take 15–25 min to San Andros (Nicholls Town), Andros Town (Fresh Creek; port of entry), Mangrove Cay (Clarence A. Bain) or Congo Town (South Andros). Wikipedia mentions the Sea-Link ferry to Morgan's Bluff and Fresh Creek and mail boats; Openferry shows no current sailings to Fresh Creek — check. • Emergency: 911 or 919; ambulance also +1 242 323 2586; BASRA +1 242 325 8864; air ambulance AAS Life-flight +1 242 377 1606. Nearest hyperbaric chamber: Bahamas Hyperbaric Centre, Western Road, Lyford Cay, Nassau — +1 242 362 5765 / 422 2434. DAN America +1-919-684-9111. • Rest day: swim at Captain Bill's Blue Hole (free) or Uncle Charlie's Blue Hole; a ~2-hour walk past blue holes and a bat cave near Caerula Mar Club (South Andros). • Accidents: blue holes and caves are overhead environments. On Abaco three divers without cavern or cave certification drowned in Big Boil Blue Hole in April 1994, on Grand Bahama two divers without cave certification drowned in a blue hole in May 1994, and in January 2003 two divers went missing in King Kong's Cavern on Andros. Go only with cave training and a local guide.