The 2-year-old husky mix was saved by rescuers who usually come to the aid of stricken marine mammals.
The dog now called Nemo was struggling to survive underneath a dock in Marina del Rey when someone spotted him at 6 a.m. and called sheriff's deputies.
Nemo was holding on to life by resting his paws on cables below the docks, but was still barely able to keep his head above the water.
They called Peter Wallerstein, director of the Marine Animal Rescue, for help.
Wallerstein is used to rescuing mammals from the unforgiving waters of the Pacific Ocean, but never any he can hold.
"My hundreds and maybe thousands of marine mammals I'm never able to bond with an animal like that," Wallestein said.
It's not known how long Nemo was actually swimming in the water. He couldn't get up on the docks because they were too high.
The dive steps on the boats were too high as well. There was no way for Nemo to get out of the water, so he could have been swimming around for hours and could have had just minutes to survive.
Skinny, freezing and likely minutes away from death, Nemo ended up at a shelter when no one claimed him.
"He is a real gem," said Marie Atake, founder and president of the Forte Animal Rescue in Marina del Rey. "He is house trained and gets along with other dogs. He's well behaved."
Nemo is at a cage-free animal shelter now, but is waiting for a good home. They're trying to find the perfect match for him.
Anyone interested in taking Nemo home, Forte Animal Rescue holds adoptions every Saturday.
Find out more on how to adopt Nemo here.