Mobula Rays in Baja California: When, Where and Why They Aggregate

Last spring, there was a moment when I looked around from the water and all I could see were mobula rays.

In front of me. Behind me. Below me. Everywhere.

Thousands of wings moving through the water, a living carpet passing underneath us with no visible end. I lifted my head to find the boat and, in the distance, several rays were launching themselves out of the water and landing back on the surface with a slap.

Erik, our captain, was laughing from the panga.

He already knew what we were about to find before we even got in.

The seasonal aggregations of Munk’s pygmy devil rays (Mobula munkiana) in the Sea of Cortez are one of Baja California Sur’s most spectacular natural events.

In this guide, I’ll explain when and where the mobula aggregations happen, why thousands of rays gather here, why they jump, the best time to see them, and how to experience them responsibly.

Quick answer: Large aggregations of Mobula munkiana occur seasonally in the southern Gulf of California, particularly around La Ventana and Ensenada de Muertos. Spring is one of the key periods, with scientific observations of reproductive behaviour peaking in May. These gatherings can involve hundreds or even thousands of rays and appear to be linked to reproduction as well as productive feeding conditions. We experience them primarily by snorkeling from small boats. Sightings and aggregation size are never guaranteed.

When is the best time to see mobula rays in Baja California?

For our expeditions, we target April through June, with May and June being particularly interesting months for large aggregations.

But there is an important distinction between the tourism “season” and what science has actually documented.

A 2023 study examining mobula rays in the southern Gulf of California recorded reproductive behaviour between March and August, with an exceptionally strong peak during May.

For Mobula munkiana specifically, 177 reproductive observations were recorded in May during the study period.

So there is good scientific evidence that spring is not simply a time when “lots of mobulas happen to be here.”

It is an important period in their reproductive ecology.

Is May or June better for mobula rays?

If your only objective were to target the scientifically documented peak in reproductive behaviour, May is particularly significant.

But wildlife does not operate on fixed dates.

We run our ocean safaris across the spring window because aggregation size, location, weather and ocean conditions can vary from year to year.

I would rather give ourselves several full days at sea during the right season than promise that one particular week will be “the best”.

EXPLORE OUR MOBULA & CETACEANS EXPEDITION

Where can you see mobula rays in Baja California?

Mobula rays can be encountered in several parts of the southern Sea of Cortez.

For us, however, the place is La Ventana.

La Ventana is a small coastal town roughly an hour from La Paz, facing Cerralvo Island.

Scientific research gives us an additional reason to consider this area exceptional.

Researchers studying mobulid reproductive behaviour along more than 300 kilometres of the eastern Baja California Peninsula found that the overwhelming majority of the reproductive events they recorded occurred around La Ventana and Ensenada de Muertos.

The study identified these areas as important reproductive habitat for mobula rays.

That scientific finding matches what local captains have been observing on the water for years.

Why La Ventana?

During winter, La Ventana is famous for wind.

The northerly winds accelerate through the channel between the Baja peninsula and Cerralvo Island, making the area internationally known for kitesurfing.

Then spring arrives.

Conditions begin to change, the ocean takes on a completely different character and the mobulas become the reason we are here.

We stay in a villa directly on the beach.

Some mornings you can open the door with a coffee in your hand and already see splashes on the horizon.

At first they look like small waves.

Then another appears.

And another.

Mobulas.

Erik comes directly to the beach with his panga, we load the gear and within minutes we are searching the Sea of Cortez.

Who is Erik, and why does local knowledge matter?

Erik is our captain in La Ventana and has spent much of his life on this sea.

If I have learned anything from working with him, it is that you don’t find mobulas with GPS. You find them with your eyes.

He has hawk eyes.

We can be moving across what looks to me like an empty ocean when he suddenly slows down and points towards a patch of water where I see absolutely nothing.

Thirty seconds later, a mobula jumps exactly there.

He reads the surface in a way that comes from years of repetition: a slightly darker patch, a change in texture, a bird behaving differently, a distant splash.

I once asked him how he knew where to go.

That morning, we saw considerably more than ten.

Local ecological knowledge like this does not replace science.

But when you combine scientific understanding with someone who has spent years watching the same stretch of ocean, it becomes incredibly powerful.

Why do thousands of mobula rays gather in Baja California?

The strongest evidence points towards reproduction as an important reason for the huge spring aggregations, while the region’s high seasonal productivity may also create favorable feeding conditions.

This is an area where we should be precise.

For years, feeding and reproduction have both been proposed as explanations for these aggregations.

We now have particularly strong evidence for the reproductive component.

Researchers observed 208 reproductive events involving Mobula munkiana in the southern Gulf of California, including courtship trains, a copulation attempt and previously undescribed reproductive behaviours.

One extraordinary observation involved a courtship vortex, with 122 rays circling together for approximately five hours while courtship groups joined and left the formation.

Most reproductive events documented in the study occurred around La Ventana and Ensenada de Muertos.

At the same time, the southern Gulf of California is highly productive during spring. Its bathymetry and seasonal oceanographic conditions can support high prey abundance close to shore.

That combination may create particularly favorable conditions for large numbers of rays to gather — providing both food and opportunities to find mates.

So the simple answer to:

What does mobula courtship look like?

This is one of the most fascinating parts of the story.

During courtship, researchers have observed mobulas forming mating trains, with males following females through the water.

In La Ventana, scientists have documented large numbers of these courtship groups occurring simultaneously.

On one survey day in May 2022, researchers counted 102 courtship trains across the area.

They have also described previously undocumented behaviours in Mobula munkiana, including the courtship vortex and “piggyback leaps” associated with pre-copulatory behaviour.

When you are floating above a huge aggregation, you therefore may not simply be looking at a random school of rays.

You may be watching one of the most important moments in their life cycle.

Why do mobula rays jump?

This is probably the question everyone asks the first time they see them.

Mobulas can launch themselves completely out of the water before landing back on the surface with a loud slap.

Different functions have been proposed for aerial behaviour in mobula rays, and jumping may not always serve the same purpose.

What is particularly interesting in La Ventana is that recent research has documented specific aerial behaviours associated with courtship, including “piggyback leaps”.

That gives us evidence that at least some jumping behaviour can occur in a reproductive context.

But I would not tell you that every jumping mobula you see is mating.

Nature is rarely that simple.

A single splash on a flat horizon can reveal an entire aggregation beneath the surface.

What other animals can you encounter during a mobula ocean safari?

This is why we call these trips ocean safaris rather than simply “mobula tours”.

We leave looking for the aggregations.

But once you spend hours on the Sea of Cortez, you never know what else the ocean will give you.

Dolphins, California sea lions, seabirds and other pelagic wildlife can all appear during the day.

And then there are the orcas.

Orcas occur in the Gulf of California and have been observed interacting with and preying upon a wide variety of marine animals.

There are also observations of orca predation on mobulid rays in the region.

What I would not say is that orcas simply “follow the mobula migration” every spring. Their movements and ecology in the Gulf of California are considerably more complex and still not fully understood.

That uncertainty is part of what makes an ocean safari an ocean safari.

You leave looking for one thing.

And sometimes the ocean gives you something completely different.

Keep reading: Orcas in the Sea of Cortez: When, Where and What We Actually Know

Can you swim with mobula rays in Baja?

Yes. Snorkeling is the way we choose to experience the large surface aggregations.

When we locate a group, the objective is not to chase it.

We observe its direction, position the boat ahead of the animals and enter the water calmly.

Then we wait.

When it works, hundreds of mobulas begin appearing out of the blue in front of you.

And then underneath you.

And then everywhere.

Can you scuba dive with the mobula aggregations?

You can encounter mobulas while scuba diving in Baja, but scuba is not how we choose to target these large spring aggregations.

The rays often travel close to the surface and can change direction quickly.

Snorkeling gives us much more mobility: we can search from the boat, reposition and enter the water when conditions are appropriate.

Spring productivity can also affect underwater visibility.

With a mask, snorkel and fins, you can watch the aggregation from above as the sunlight moves between hundreds of wings.

For this particular phenomenon, that is exactly where I want to be.

Do you need to be a freediver?

No.

You do not need a freediving certification or advanced breath-hold skills.

Most of the encounter happens close to the surface.

You should, however, be comfortable swimming with a mask, snorkel and fins in open water and getting in and out of a small boat repeatedly.

If you are comfortable making short duck dives, you may enjoy another perspective on the aggregation, but it is not necessary.

How many days do you need to see the mobula aggregations?

I would give yourself several days.

The mobulas may be close to shore one morning and much farther away the next.

A huge aggregation can appear one day and become far more dispersed the following morning.

Wind and sea conditions matter too.

That is why our expeditions are built around multiple full ocean-safari days, rather than a single attempt.

With wildlife, time is one of the most valuable things you can give yourself.

SEE HOW WE EXPERIENCE THE MOBULA AGGREGATION

Are mobula sightings guaranteed?

No.

These are wild animals responding to changing conditions.

Even during the right season, aggregation size and location can vary enormously.

What we can do is travel during a favorable seasonal window, spend enough time at sea and work with local captains who understand the area.

But we will never promise an animal that we cannot control.

Are mobula rays dangerous?

Mobula rays are not animals we consider dangerous to swimmers when encountered responsibly.

They are filter-feeding rays and do not possess the venomous tail spine associated with some stingrays.

The greater practical considerations during an ocean safari are the open-ocean environment, boat entries and exits, wind, waves and your own comfort in the water.

As with any wildlife encounter, we give the animals space and never touch or chase them.

What is the water temperature during mobula season?

During our spring expeditions around La Ventana, we generally experience increasingly warm water as the season progresses, although local conditions and upwelling can create considerable variation.

For planning purposes, we normally recommend a 3–5 mm wetsuit, with more thermal protection early in the season or for anyone who gets cold easily.

I would treat exact temperature ranges as operational observations rather than guarantees.

Ocean conditions can change quickly here.

How do you experience mobula aggregations responsibly?

Seeing thousands of rays does not mean we can behave as if our presence has no effect.

Quite the opposite.

Scientific research now shows that La Ventana and Ensenada de Muertos are important areas for reproductive behaviour.

That makes responsible encounters even more important.

At Mind the Seas, the boat does not cut through an aggregation or chase it.

We try to understand the direction the animals are travelling, position ourselves ahead of them and allow the rays to decide whether they pass near us.

We enter calmly and in small groups.

We do not touch them.

We do not swim aggressively after them.

And if the animals change direction or disperse because of our presence, we back away.

I have watched Erik switch off the engine and wait ten minutes for an aggregation to settle before allowing us to enter.

Sometimes the best decision you can make during a wildlife encounter is to do absolutely nothing.

EXPLORE THE FULL MOBULA & CETACEANS EXPEDITION

How we experience Baja’s mobula season at Mind the Seas

The mobulas are the reason we choose this particular window.

But they are not the only reason we spend our days at sea.

Our Mobula & Cetaceans expedition is built as an ocean safari.

We stay by the water in La Ventana and spend our days searching the Sea of Cortez with local captains, following what the ocean is doing rather than trying to force it into a fixed wildlife checklist.

The mobula aggregations are the central natural event.

Everything else is the unknown.

And that is exactly the point.

My personal take

Mobulas taught me something I did not expect:

abundance can be quiet.

There is no hunt unfolding around you like the Sardine Run. There is no intimate encounter like watching a gray whale approach a boat.

There are simply thousands of animals moving past you without paying any attention to you at all.

And somehow that makes you feel incredibly small.

If you come, come during the spring window, bring patience and think of it as an ocean safari rather than an attraction with a guaranteed outcome.

Stay close to the sea.

Wake up early.

Look at the horizon while you drink your coffee.

And when Erik suddenly slows the boat and points towards a patch of water where you cannot see anything…

get ready.

Scientific sources and further reading

Palacios et al. — Reproductive behavior, seasonality, and distribution of three devil ray species (Mobula mobular, M. thurstoni, and M. munkiana) in the Southern Gulf of California, Mexico. Marine Biology (2023).

This study documented 221 reproductive events involving three mobula species, including 208 involving Mobula munkiana. Most observations occurred around La Ventana and Ensenada de Muertos, with reproductive activity peaking strongly in May.

Stewart et al. — Description of first nursery area for a pygmy devil ray species (Mobula munkiana) in the Gulf of California, Mexico. Scientific Reports (2021).

Research describing M. munkiana habitat use, diet, aggregative behaviour and the first documented nursery area for the species in the Gulf of California.

Mexican biodiversity and conservation regulations

Mobula munkiana is recognized as a protected species under Mexican regulation.