LA JOLLA, Calif. -- Just beyond the breakers at La Jolla Shores Beach, hundreds of dark figures cruise through the sandy shallows like a scene in a horror movie.
In most cases, the sight of one shark, much less hundreds, would spark panic.
The leopard sharks of La Jolla induce a different response.
Instead of racing toward shore, visitors here head out toward the deeper water to get a closer look.
And for those who get the chance to swim with the sharks, the experience is unforgettable.
"I've been doing it for years and I still go out and swim with them," said Ezekiel Morphis of HBK Sports, which offers kayaking and snorkeling tours with the sharks. "I think it's awesome."
The leopard sharks come close to shore from June to early December, peaking between August and September, when hundreds congregate along a small stretch of this beach north of San Diego.
The sharks are mostly pregnant females and juveniles are rarely seen, so scientists believe they gather here to help with the gestation process.
Because of a submarine canyon just offshore, the waves at La Jolla Shores tend to be smaller, which keeps the colder water of the deep from mixing with the warmer water of the shallows. With the small waves and warm water, it becomes a perfect place for the coldblooded leopard sharks to hang out before giving birth someplace else.
"What these females are essentially doing is incubating," said Andrew Nosal, a postdoctoral researcher at the Birch Aquarium in La Jolla. "They've developing embryos like a mother bird would sit on the eggs to keep them to warm."
That's all interesting, but we know what you're thinking: Isn't it dangerous to swim with sharks in the open ocean?
No, at least not with these sharks.
Leopard sharks, unlike larger, fear-inducing species like the great white, are nonaggressive and actually a bit timid, darting away whenever there's a commotion in the water.
Leopard sharks also have small mouths and teeth -- they feed on crustaceans, shrimp and bony fish -- so even if they did bite, it wouldn't cause nearly as much damage as some of the larger fish swimming around.
It's still the ocean, though, so there's always the chance larger sharks might come in to feed, but attacks on leopard sharks near La Jolla are almost unheard of.
"There's always a small risk of danger when you swim with animals," Nosal said. "But leopard sharks are generally nonaggressive. They're actually quit skittish and can be quite difficult for snorkelers to approach. The best way to swim with these animals is to float because kicking or any kind of noise tends to scare them away."
Despite knowing the sharks are docile, it still can be a bit unsettling on the first encounter, even for the adventurously inclined.
On days with calm winds and waves, the water is exceptionally clear, making it easy to see the distinctive dark stripes and spots on the backs of the sharks as they swim around people's legs or underneath those who are floating on the surface or in kayaks.
When the water gets rougher, the sand and seaweed stir and swirl around, sometimes dropping the visibility to a few feet. The cloudy water creates an eerie underwater scene, the shadowy figures of the leopard sharks that reach up to five feet long seeming to appear out of nowhere and disappearing just as quickly.
Clear water or not, the reaction for first-timers hits a wide spectrum.
"We get everything from not much reaction to absolute terror to absolute elation," Morphis said. "I think people have a lot of interesting views on sharks whether they've been educated that they're fairly harmless or not."
Whatever fear people might have usually doesn't last long.
After a few minutes of watching sharks swim around their legs or below them, the fear is usually taken over by amazement, almost a feeling of one with nature as these majestic animals cruise around in the open ocean.
"I like to think of leopard sharks as a friendly ambassador for sharks in general," Nosal said. "It's a really great way for people to overcome their fear of sharks, to see that not all species are potentially dangerous, that this one really is harmless, yet they really do look like sharks. These are not rinky-dink animals. They look like sharks, they're rather large and to see so many at one site is really impressive. I've been out there and been surrounded by easily 50 of these animals at once and it's very impressive."