The question is: Do people need to be worried? Well, this particular type of shark can grow up to 10 feet long, and scientists say they can be aggressive.
Divers have been spotting the sevengill shark more frequently lately.
"I can't explain how cool this is," said Steve Murvine, who has shot stills and video of the sharks.
Murvine has been diving in San Diego for 15 years but just recently started seeing the sevengill. In fact, he saw two just last weekend.
"I've seen them since 2007," Murvine said. "I've probably had eight or nine different encounters."
He isn't the only one who's spotted them.
"All of a sudden, this really large shark just appeared between us," diver Mike Bear said. "He had to be 7-9 feet long."
Bear has been keeping track of the local sightings of the sharks, which can be recognized by their spotty skin and long tails.
"We've seen an uptake, and nobody is really sure why," Bear said. "Over a dozen in the last year, and those are just the ones that we've recorded."
Scientists say the sharks have always been in the area but it's possible there are more divers now or that the sharks have changed their behavior and are coming in closer to shore.
So, is that something to worry about?
"Just be ready, because they can be pretty bold and confident, and sometimes they can come pretty darn close to you," said Andy Nosal of Scripps Oceanography.
Scientists say that the sharks are rarely a danger as long as humans leave them alone.
"They can be dangerous if provoked," Nosal said. "There's only been a handful of attacks in the last few centuries on humans."
Spotting one of the sharks can be the highlight of any San Diego dive, as long as the divers know how to act.
"If you see a sevengill, stay calm and enjoy it, because it's a pretty rare thing to actually see them," Nosal said.
A leading expert on sevengill sharks said the sharks have been seen in water as shallow as 1 to 2 feet deep.