Sorting the nine bays before you book
Huatulco's coastline is a series of nine bays folded into the Sierra Madre del Sur between the town of Santa María Huatulco and the open Pacific. The developed core, Bahías de Huatulco, spreads around Santa Cruz, Chahué, Tangolunda, Conejos and Maguey, with the rest reachable mainly by water. Most boats leave from the Santa Cruz marina beside the Plaza Principal, a short walk from the hotels clustered around Boulevard Benito Juárez. Trips run roughly 8am to 3pm; afternoon seas pick up from December to March, so morning departures are calmer.
The standard full-day tour covers seven bays in about six hours, with two or three swim stops. A shorter half-day concentrates on four bays and one beach. Boats range from open lanchas with a shade canopy to catamarans carrying forty or more. The lancha is cheaper and can nose into coves the big catamarans skip; the catamaran has shade, a head and lunch. If you are prone to seasickness, take the catamaran and sit amidships, or choose the half-day that stays inside the sheltered bays.
Bahía Maguey, Órgano and Cacaluta
Maguey comes first on most itineraries and is the easiest swim of the day: a curved grey-sand beach with palapa restaurants behind it and snorkelling over rocks at the eastern end. It is busy by noon in the Christmas-to-Easter high season, so ask your captain to stop early. Órgano is a narrow, cliff-walled bay with almost no beach at high tide; boats idle close to the rock while you look up at the organ-pipe formations. It is a photo stop rather than a swim, and worth having your camera ready.
Cacaluta is the highlight for many visitors and the one bay where you should expect no development at all. A long beach backs onto a lagoon and mangroves, with the small Isla Cacaluta offshore. Swimming is good at the southern end; currents run along the northern headland. Some tours land here, others only pass by, so confirm before booking if a beach stop matters to you. Coral and fish are visible off the rocks, but visibility is best between November and May, before summer rain clouds the water.
Chachacual, San Agustín and the open-water bays
Chachacual is the snorkelling stop on most full-day routes, inside a protected marine area with a shallow reef close to shore. There is no development and, depending on the operator, no facilities, so bring water and use the boat's ladder. San Agustín sits beyond the Huatulco National Park boundary and is the largest of the outer bays, with a village, a long beach and a handful of restaurants. Some tours land for lunch here; the ride from Santa Cruz takes about forty-five minutes in a lancha, longer in a catamaran.
Beyond San Agustín the coast turns wilder towards Bajos de Coyula and the open Pacific. Few day tours go that far, and the ones that do are weather-dependent. If you want the empty-beach experience without a long crossing, book a panga from the village pier at Santa Cruz to Playa La Entrega, ten minutes away, where the snorkelling is good and the palapas are close to the sand. It is the cheapest way to see a national-park beach on your own schedule.
Practical choices: shoes, boats and hotel bases
Boats are boarded from the sand or a small pier, so wear sandals and carry what you need in a dry bag. Most tours include a life jacket and snorkel gear; fins are often an extra and masks are well used, so bring your own if you snorkel seriously. Sunscreen must be reef-safe inside the national park, and shade is limited on lanchas between stops. Cash is useful at Maguey and San Agustín for drinks and grilled fish; card readers are unreliable where there is any signal at all.
Where you sleep shapes the trip. Hotels in Tangolunda sit above a golf course and a ten-minute taxi from the Santa Cruz marina; Santa Cruz itself puts you within walking distance of the boats and the restaurants around the plaza. Chahué is quieter and a short drive from both. For a three-night stay built around one boat day and two beach days, I would book Santa Cruz for the convenience, then move to Tangolunda for a resort finish if the budget allows. February and March give the steadiest weather and the most reliable crossings.