This is the moment a woman caught her fish dinner within seconds using nothing - but a tiny sand crab as bait.

Kaitlyn Bui, 27, taught herself how to fish by watching YouTube videos.

She recorded herself catching a striped bass and a large barred surf perch just moments after casting her line off Ocean Beach in San Francisco, California.

Video shows Kaitlyn casting her rod and getting a bite almost instantly, before she reels in her catch.

Kaitlyn, a content creator from San Francisco, said: "The perch was surprisingly large and fed a group."

"It was 14-inches - the biggest I've ever caught. And a 20-inch striped bass - just over the legal limit."

"Perch gets a bad rep for being mushy, but deep-fried? It's pretty dang good."

Kaitlyn, who has been been fishing for two years, took it up after someone told her she "couldn't do it"."

She now documents her fishing trips online, turning her hobby into a profession.

While catching a fish that fast is rare, she says, it's not impossible.

Kaitlyn said: "I didn't grow up outdoorsy. "

"One day someone told me ‘cute little girls don't need to get their hands dirty', so I picked up a rod out of spite and haven't looked back."

"I taught myself by watching YouTube videos and now I'm completely obsessed. "

"I fish alone most of the time. It's my way to decompress."

Kaitlyn used a tiny live sand crab as bait and said she wasn't expecting much, but walked home with a feast that fed her family.

She explained her technique is fairly traditional but adapted to suit her.

Kaitlyn said: "Crabs are totally free and one of the most effective baits you can use out here. "

"Fish naturally eat them, so it just makes sense."

Kaitlyn usually fishes during high tide - the time when fish are most active -

and said sometimes the bites are instant, while other days she might wait for hours.

She said: "Sometimes it's seconds, sometimes it's hours. "

"It all depends on the day and how stubborn I'm feeling."

"But that one was wild! Windy days are the worst. I don't catch fish - just a cold."