So what are they and how did they get here?
They are the type of jellyfish beach goers do not often see.
The jellyfish washing up are not the ones with long tentacles like most people are use to seeing, and they are not dangerous to touch like the ones with long tentacles.
They are tiny clear and blue creatures, and their official name is Velella-Velella. They are a unique type of jellyfish and are commonly known as the wind sailors.
"They actually have a sail made up of material that is very hardened. That sail pushes them with the wind in a certain direction," said Leslee Matsushige, an Associate Curator of Fishes at Birch Aquarium.
She said the species lives on the surface of the ocean, miles away in the open ocean, and once in a while, they will wash up along San Diego beaches.
"When we have large storms and we have a lot of onshore winds pushing the sail by the wind sailors onto shore. We will see them. Normally, when you see jellyfish on the beach, your first instinct is to stay away but in this case, they aren't harmful to humans. That's because you can't feel them sting," she said.
Experts did warn beach goers to handle them with care, especially those who are sensitive.
Scientists said the bottom color of the jellyfish can range from blue to turquoise, and because they live on the surface of the ocean, it helps them blend in, which protects them form predators.
There have been similar sightings in Oregon and Washington state.