Los Cabos Diving: A 1973 Decree at the Arch, a Written Rulebook at Cabo Pulmo

Los Cabos diving splits between two protected areas with opposite rulebooks

Most first dives in Los Cabos happen off Land’s End, a short boat ride from the marina at Cabo San Lucas. That water is the Área de Protección de Flora y Fauna Cabo San Lucas, 3,996.04 hectares in CONANP’s record, of which 3,787.99 are sea. It began as a “submarine refuge” by a decree published on 29 November 1973 and was given its current category on 7 June 2000.

The second area is Cabo Pulmo National Park, declared a marine national park on 6 June 1995 off the coast of the municipality of Los Cabos, with 7,111 hectares, and recategorized as a national park by the same 2000 agreement. Measured between the coordinates in the two instruments, it sits roughly 75 kilometers north-east of the Arch in a straight line.

The two are regulated in completely different ways. Cabo Pulmo has a management program, published in the Diario Oficial de la Federación on 13 November 2009, whose administrative rules set how many divers go down per instructor, where boats tie up and when the reef closes for the night. The Arch area has its 1973 decree and not much else, which is why a rule you hear quoted in Cabo San Lucas may belong to a park 75 kilometers away.

The Arch at Los Cabos sits under a 1973 decree that bans fishing and anchoring

The decree creating the refuge has six short articles. Article 2 draws a box: north to the parallel 22°54′, south to 22°50′50″, west to the meridian 109°54′ and east to 109°50′. Article 3 says that fishing of all species in that zone “queda estrictamente prohibida”, strictly prohibited.

Article 4 is the one a dive boat meets. It is “terminantemente prohibido anclar”, absolutely forbidden to anchor, or to throw toxic or harmful substances, use explosives, or leave fishing waste on the adjacent beaches. The recitals give the reason for all of it: to keep “con toda originalidad” the spectacle of the sand falls on the seabed, to let scientists study erosion in the submarine canyons, and to keep fish in the water so that the place would become “un gran atractivo turístico”.

The 2000 agreement that renamed the refuge did not wipe the decree out. Its article 3 subjects each area to the federal environmental law for its category “y lo estipulado en los decretos correspondientes”, and its first transitory article repeals only those provisions of the old decrees that oppose the agreement itself.

Practice has moved on regardless. CONANP’s 2023 study of the area records that cruise ships anchor at four positions set by the port administration within the harbor limits, and that those anchoring points lie inside the protected polygon. The same study describes a live-bait fishery of a little over 30 fishermen working the area between 2:00 and 6:00, and proposes that it continue.

No management program has been published for the Los Cabos Arch area

At Cabo Pulmo, every dive rule lives in the park’s management program. CONANP’s information system lists the program for Cabo San Lucas as “Resumen DOF no publicado / PM elaborado”: drafted, never published in the official gazette. The download link on that record opens a single page that reads “Programa de manejo no publicado”. The record was last updated on 17 July 2026.

A draft does exist. CONANP put one out for public consultation in August 2012, marked “borrador” on every page. A program takes effect on publication, as the 2009 notice for Cabo Pulmo spells out, so any figure for divers per guide, mooring time or glove use at the Arch that is presented as a park rule has no published rule behind it.

CONANP says as much itself. Its 2023 study, written to justify changing the 1973 decree, states that for diving the mooring sites, the hours and the carrying capacity of each site “serán determinados en el programa de manejo del área que en su momento sea expedido”: they will be set in the program once it is issued. Until then, the number that does apply on a guided dive comes from the federal tourism standard NOM-012-TUR-2016, whose table allows eight certified divers per guide in optimal conditions.

The study also proposes a bigger area. It would add 52.98 hectares of the bay and 437.94 hectares of coral and rocky reef to the north, cut out 173.02 hectares of land that the 1973 box drew over the town, and bring the total to 4,313.94 hectares, with a zoning the old decree never had. The notice opening it for comment appeared in the Diario Oficial on 23 March 2023. CONANP’s record still shows the 1973 decree and 3,996.04 hectares.

The Los Cabos sand falls pour into a canyon whose head starts 20 meters down

The reason the area exists is under the water. CONANP’s study credits Conrad Limbaugh with finding the sand falls in 1959, when a storm had stripped about 30 inches of sand off Playa del Amor and he saw sand pouring over rock like a submerged waterfall at a depth of 110 feet, about 30 meters. The falls run from Playa del Amor to Playa del Pelícano, and the one with the largest flow is the one nearest Playa del Amor.

They drain into the San Lucas submarine canyon. The study gives its main axis a length of 3,900 meters, reaching depths beyond 2,000 meters, with walls showing escarpments of up to 230 meters. Its head sits a few meters off the beach at a depth of about 20 meters, which leaves the shelf in the bay only 1.5 kilometers wide. A US Navy estimate the study cites puts the sand lost down the canyon at around 100,000 cubic meters a year.

The same study reports a coral survey of six dive sites. Coral cover was below 20 percent at every one, highest at Faro Cabeza de Ballena, Barco Varado and Piedra Pelícano. In the northern sites three species of Pocillopora made up more than 80 percent of the coral, and Piedra Pelícano, Pelican Rock to most visitors, was the only site with all five coral groups the survey counted.

The study frames that as acceptable rather than poor. It compares it with Cabo Pulmo, where average coral cover in 2016 was 18 percent, and adds that steeper bottoms around Los Cabos leave less room for corals to settle than the gentler slope at Pulmo. For buoyancy practice before a wall like this, the buoyancy control guide covers the basics.

Cabo Pulmo, the Los Cabos coral reef, is a no-take zone only in part

The 1995 decree is unusually direct about why Cabo Pulmo matters. Its recitals call the reef one of the few reef areas in the eastern Pacific and the only one in the Gulf of California, and say it could be the oldest reef on the American Pacific coast, with a Late Pleistocene marine terrace in the bay dated from the corals in it.

Article 7 of the decree bans anchoring boats, platforms or infrastructure of any kind, “particularmente en las zonas arrecifales”, along with dredging, explosives and the extraction of coral. The decree gave the authorities 365 working days to write the management program. It was published fourteen years later, in November 2009.

Cabo Pulmo is often called a no-take reserve, including in the 2011 study that made its name. The 2009 program is narrower. Fishing of any kind is prohibited in preservation subzone 1, the 2,555.68 hectares over the reef itself, including Las Tachuelas, Los Mangles and the main reef off the village with Los Morros, El Bajo and La Esperanza. Anchoring is banned there too.

The remaining 4,557.37 hectares of sea are a sustainable-use subzone. There, the program permits anchoring of small boats, bait collection by residents with hook and line, domestic-consumption fishing, and sport fishing in catch-and-release mode. Divers share that outer water with rods.

What the closure did on the reef is documented. Aburto-Oropeza and co-authors, writing in PLOS ONE in 2011, measured total fish biomass rising from 0.75 tonnes per hectare in 1999 to 4.24 in 2009, an increase of 463 percent. Top predators grew elevenfold, and fish biomass in other protected and open-access areas of the Gulf did not change significantly over the same decade.

Six divers per instructor and no gloves: the Cabo Pulmo rules on a Los Cabos trip

Rule 32 sets the daytime ratio by subzone. On the reef, preservation subzone 1, one instructor may take six scuba divers or eight snorkelers. In the outer sustainable-use subzone the figure is eight for both. The rule adds that the instructor or leader must stay with the group for the whole dive.

Night is tighter. Rule 26 splits the diving day into daytime, 6:00 to 19:00, and night, 19:00 to 22:00, so no dive in the park runs later than that. Rule 33 caps a night dive at three scuba divers or five snorkelers per instructor in either subzone. The night diving guide covers the skills; the ratio here is the park’s.

Rule 30 is two sentences: keep at least 2.5 meters from rock or coral formations, and gloves are prohibited “a excepción de lo establecido en la regla 33”. Rule 33 is the night-ratio table and says nothing about gloves. As published, the exception points at nothing, so there is no written case in which gloves are allowed.

Rules 34 and 35 grade the reef units by experience. Las Tachuelas, Islote Piedra, Lobera and one Cabo Pulmo unit need divers certified with at least one star or equivalent. Los Morros and El Bajo, the Barco Hundido wreck, La Esperanza and Barra No. 5, Punto, Los Frailes and a second Cabo Pulmo unit need at least three stars or equivalent. The program does not say whose star system it means, so bring your logbook as well as your card.

The boat rules are just as specific. Only small boats, up to ten passengers and under 12 meters, may run dive trips (rule 47). Each mooring buoy takes two boats per hour, and a boat that finds it taken must wait more than 50 meters off, with nobody in the water until it is tied on (rule 48). From 200 meters before the buoys the limit is 4 knots (rule 50). Anchoring is allowed only on sand in marked sites (rule 56).

Snorkelers on the reef must wear a life jacket, guides included (rule 27), and every diver needs a certification from an internationally recognized agency and a certified guide or instructor (rule 28). Rule 29 still sends operators to NOM-05-TUR-2003 for equipment, a standard cancelled in 2016; the La Paz diving guide sets out what replaced it.

Los Cabos humpback season closes 2 kilometers around the Arch to whale watching

In winter, humpbacks are part of the Los Cabos dive calendar. The whale-watching standard NOM-131-SEMARNAT-2010 states in its recitals that humpbacks are especially concentrated in the Los Cabos region during their winter breeding migration, and SEMARNAT publishes a notice each year fixing the season and the restricted zones.

For 2025-26 the notice, published on 10 October 2025, opened the season in the Cabo San Lucas protected area and San José del Cabo from 15 December 2025 to 30 April 2026. It set two restricted zones there “debido a la excesiva navegación”, because of excessive boat traffic: the northern part of the polygon in the port area, including 2 kilometers around the Arch, and a 1-kilometer strip seaward from Punta Ballenas. At Cabo Pulmo it restricted a coastal strip 3.5 kilometers wide.

The standard itself is blunt about mixing the two activities. Section 4.19(d) says that during whale watching nobody may fish, dive, swim, water-ski or parasail. A boat running a whale trip cannot put you in the water with the animals, whatever is on offer at the dock. The notice for 2026-27 had not been published by 25 September 2026, so check the dates for the season you travel in.

Water off Los Cabos runs from about 19°C to 30.5°C, warmest from July to November

CONANP’s study used NOAA’s reconstructed monthly sea-surface temperature record from 1870 to 2015 for the square around Cabo San Lucas. The long-run mean was 24.38°C, give or take 2.68, with a sharp split between warm months, July to November, and cool ones, December to June. Monthly values reached a maximum of 30.5°C in some years and a minimum of 19°C.

El Niño years push the surface close to or above 30°C. A separate series the study cites puts its historical low at 20.07°C in February 1989. The study also finds more warm anomalies since 1990. In practice the cool half is also whale season, which is when a proper wetsuit earns its place.

The warm half also overlaps the eastern Pacific hurricane season. The La Paz guide sets out its dates from the US National Hurricane Center and what Hurricane Odile did to the peninsula in 2014.

Gordo Banks off Los Cabos is where pregnant whale sharks turn up

The seamount that Los Cabos boats run to for big animals is called Banco Gordo in the literature, sold in English as Gordo or Gorda Banks. The best peer-reviewed account of what visits it comes from a 2017 tagging study in PeerJ by Ramírez-Macías and co-authors, and it is about whale sharks rather than the hammerheads on the posters.

The paper describes adults, “specifically pregnant females”, as seasonally present at Banco Gordo and at Isla Espíritu Santo, while juveniles are found in coastal areas. One pregnant shark tagged at Banco Gordo on 8 May 2012 was photographed at Roca Partida in the Revillagigedo Islands on 22 November 2012, still pregnant.

That makes this a different encounter from the one in the Bahía de La Paz, where the same paper describes mostly juvenile males feeding in shallow water. It also named Banco Gordo in 2017 as one of two of its five whale shark sites that remained unprotected. For how this compares with other places, see the whale shark destinations page.

Los Cabos park fees in 2026: 125 pesos at the Arch and Cabo Pulmo, 3,760 at Revillagigedo

Article 198 of the Ley Federal de Derechos lists both Los Cabos parks by name in fracción I Ter, the tier for areas of medium carrying capacity. For 2026 that is 125.32 pesos per person per day for scuba, snorkeling, boat tours and other non-extractive use, which the article rounds to multiples of 5 pesos, so 125 pesos in practice. The payment falls on the permit-holding operator; the Cancún diving guide explains how that works.

Mexican nationals and foreign residents who can prove it pay half. Children under 12, people with disabilities, pensioners and holders of the INAPAM seniors card pay nothing. Rule 12 of the Cabo Pulmo program repeats the fee duty for tourism operators and makes them carry their CONANP authorization during the activity and show it on request.

Revillagigedo is priced on its own. The national park declared on 27 November 2017, which its program places 540 kilometers from the municipality of Los Cabos, is one of two areas in fracción I Bis: 3,759.29 pesos per person per day, rounded to 3,760. The annual pass that covers every other protected area for the same 3,759.29 pesos excludes it.

Its 2018 program is strict about diving too. Groups are capped at eight divers per guide, each diver may make at most four dives a day, and diving runs from 7:00 to 30 minutes before sunset, so night diving is not allowed. Two groups may not dive the same site at once, and rule 34 says to avoid jumping in to see whales, especially with calves. The liveaboard destinations page covers the trip itself.

The Los Cabos recompression chamber is in Cabo San Lucas

The Subaquatic Safety Services network runs a recompression chamber in Cabo San Lucas, which it describes as its west-coast chamber since 1996. Its own page gives the address as Adolfo López Mateos Street, between Leona Vicario and José María Morelos, Ejidal Chamizal, 23470 Cabo San Lucas, and the emergency line as +52 624 160 9393, with +52 624 143 3666 as a second number, both as read on 25 September 2026.

The network says it works with the Red Cross, the fire brigade and the coast guard on evacuations, and uses double-lock multiplace chambers. Hospital H+ Los Cabos, at kilometer 24.5 of the Transpeninsular highway in San José del Cabo, describes its own chamber as a monoplace medical unit and does not mention diving on its page, so ask before assuming it treats divers.

NOM-012-TUR-2016 requires every dive operator to carry a first-aid kit and oxygen equipment (8.3) and to hold a written contingency plan that identifies the nearest place of medical care (8.4). Ask to see that plan, ask how the boat gets you back from Cabo Pulmo, and check that your dive insurance covers the chamber and the evacuation.

Six dive businesses are listed for Los Cabos, filed under four different towns

The Los Cabos operator list, compiled on 21 September 2026, holds six businesses. Four are published by SSI in its register of affiliated centers, and SSI files them under four different towns: Cabo San Lucas, San José del Cabo, “Cabo Pulmas”, which reads as Cabo Pulmo, and La Paz. The town field is where the register files a business, not proof of where its boats go.

The other two are Green Fins digital members, which means they completed a self-evaluation and were not assessed in person. Five of the six publish a website, and SSI rates two of its four centers for Freediving, which describes the listing rather than a course running this season.

None of that says whether a business holds the CONANP authorization that rule 12 at Cabo Pulmo requires, and that authorization is not published as a list. Ask for it, and for the contingency plan. Which registers can be read explains what each source can and cannot tell you.