Los Arcos: A National Marine Park, a Cliff Jump and a Glow Nobody Can Promise

The rocks look like a photo opportunity from the boat. What they are is a legal designation, and that is the reason there is anything worth putting your face in the water for.

What is actually out there

Five granite islets, twelve kilometres south of Puerto Vallarta, off the mouth of Mismaloya. The two largest stand 43 to 54 metres above the water; the biggest covers around 40,000 square metres. Sea arches run through them at the waterline – some navigable by small boat, some not – and that is where the name comes from.

The water around them is unusually deep for a bay this size. Published figures put it at up to 480 metres, possibly the deepest point in Banderas Bay, which is why a snorkelling stop of a few metres’ depth sits within sight of something that drops away entirely.

The dates that made the difference

Los Arcos was declared a refuge zone for the protection of marine flora and fauna by federal decree published on 28 July 1975, and reclassified as a national marine park in 1984.

The practical consequence is short: fishing is prohibited there. That single rule, kept for half a century, is the whole explanation for why a snorkeller sees king angelfish, giant damselfish, octopus and the occasional seahorse a quarter of an hour from a city of a quarter of a million people. It is not luck and it is not feeding. It is a fifty-year-old ban.

Above the surface the rocks carry ospreys, pelicans, cormorants and blue-footed boobies. Between December and March, humpbacks, dolphins and occasionally orcas pass through the same water on their own business – which is a different trip with different legal rules and a minimum distance attached to it.

The trips, and what separates them

Our Los Arcos page carries 24 trips from €38.66, median €79.17, and the wider snorkelling category runs to 32 from €32.51. Four shapes of day are on offer.

The daytime snorkelling run. The 5 Islands of Los Arcos boat tour with snorkelling is €42.18 with 391 reviews at 4.7 – by a distance the most-reviewed trip out here, and the one to book if you want the fish and nothing complicated.

The one with the cliff jump. Mismaloya: snorkelling, cliff jumping and beach tour is €38.66 at 4.9 stars from 44 reviews and starts at Mismaloya rather than the city marina. The jump is the part people book it for and also the part to ask about: the height, whether it runs on the day, and whether anyone is expected to do it are answers the operator has and a listing page does not. Nobody has to jump, and a trip where the guide treats that as negotiable is the wrong trip.

The evening ones. Bioluminescence and sunset boat tour to Los Arcos is €39.66, 4.7 stars from 108 reviews; sunset boat tour and bioluminescence swim is €41.30 at 4.8 from 48; and a Mismaloya departure of the same idea runs €60.63, 4.7 from 34 reviews.

On the water rather than in a boat. The bioluminescent waters kayak and cave tour is €84.27, 4.8 stars from 101 reviews – level with the sunset boat tour above, but on twice as many reviews, and roughly double the price, for a paddle rather than a deck. At the far end, a private boat to Los Arcos is €431.26 for the boat.

The glow: check the moon before you check the reviews

The light comes from dinoflagellates – single-celled organisms that flash when the water around them is disturbed. A paddle stroke, a hand pulled through the surface, a fish moving off. It is real, it happens here, and the darker, less built-up stretches of the bay around Los Arcos are where it shows best.

It is also the single most oversold thing on this coast.

What it depends on is plankton concentration, water conditions and how much moonlight is falling on the sea. Around a new moon, a faint glow is visible. On a clear night at full moon, the same water with the same plankton in it will show you very little, because your eyes are competing with the sky.

That is a calendar, not a lottery, and it is the one variable you can check yourself before you book. Every operator selling an evening trip is selling the same water; none of them controls the moon, and any page that guarantees the glow is guaranteeing something outside its power.

The honest version: on the right night it is remarkable, on the wrong night you have had a sunset boat trip, and a sunset boat trip in Banderas Bay is not a bad evening. Book it that way round and you will not be disappointed either way.

Getting to Mismaloya without a tour

Mismaloya is on the city bus network. The orange-and-white C01 leaves from the corner of Basilio Badillo and Constitución in the Zona Romántica, and the urban fare rose from 10 to 11 pesos on 1 April 2026 – older pages still quote the ten.

That gets you to the beach, a bar, and a view of the islets. It does not get you to them: Los Arcos sits offshore and the snorkelling is done from a boat or a kayak. Walking down to Mismaloya and arranging something at the beach is a real option; turning up expecting to swim out is not.

What to expect, stated plainly

A snorkelling stop here is shallow, short and busy with fish, in water that is usually clear and occasionally is not. Visibility moves with swell and rain, and no operator can promise you a given day. The birds are on the rocks year-round. The whales are seasonal and belong to a different set of rules.

The one thing you can count on is the reason the place works at all, and it is written into a decree from 1975.

If you would rather reach the water on foot, the hidden beaches walk south of town ends at snorkelling of its own. With children along, the turtle release and what else works with kids is the calmer evening. And for the sunset without the swim, sunset cruises number 10 from €39.66.