Two men were rescued from Mendocino Bay after they were swept into the ocean by high waves at Big River Beach Thursday evening.

After being pulled into the cold, choppy water while exploring the rocky coast with friends, one man climbed onto a large offshore rock. The other man was either swept or swam into deep sea cave on shore, Mendocino Volunteer Fire Department spokesperson Sally Swan said in a statement released Friday.

Mendocino firefighters took the lead on the rescue efforts, dispatching two personal watercraft and a boat. Cal Fire and the Sonoma County Sheriff’s Office sent rescue helicopters to assist in the operation.

Firefighter Josh Miller jumped from the rescue boat to the large offshore rock and helped the stranded man to safety.

To retrieve the other man, rescue swimmer Cap. Paulo Andrade swam 200 feet into the cave while tethered to a personal watercraft. The inside of the cavern was so dark that Andrade had to locate the man by the sound of his voice while contending with floating logs and surging water, Swan said.

The man pulled from the cave was flown by helicopter to Santa Rosa Memorial Hospital for severe hypothermia and moderate to severe injuries, said Swan. The other was taken to Mendocino Coast District Hospital for mild hypothermia and trauma.

You can reach Staff Writer Nick Rahaim at 707-521-5203 or nick.rahaim@pressdemocrat.com. On Twitter @nrahaim.