A little after 10 a.m. -- more than six hours into his swim -- Chase said cold water and jellyfish, which were biting him in the face and arms, got the best of his body and he knew it was time to stop.
"I wasn't in the advanced stage of hypothermia, but the fact that I was curling up to stay warm I knew I was in bad shape," Chase said.
Chase updated followers on Twitter for the NBC station in Salinas during his swim. One Tweet, issued a couple hours before his attempt ended, read:
"Less jellies now. Water about 59. Shivered a little when stopped to eat. Water like glass."
An encounter with jellyfish is something Chase knew was a possibility, but at times during the swim their stinging attack became unbearable.
"Some had tentacles, and it was like leather straps around my arms and torso," Chase said.
Chase was attempting to become only the second known person to complete the solo swim. Cindy Cleveland swam across Monterey Bay 30 years ago.
"It's almost like an unscaled peak. Cindy pioneered it and I'm going to try to duplicate her route," Chase had said on Tuesday.
The swimmer from New Jersey said, however, that he plans to return to the Central Coast and tackle the chilly waters of Monterey Bay sometime next year.
This article originally appeared on KSBW.com.