Rescue officials are hopeful that a surfer who was plucked from the sea after more than 30 hours adrift off the western coast of Scotland will make a full recovery despite severe hypothermia.

Matthew Bryce was being treated at Belfast Hospital in Northern Ireland on Tuesday after an intense search ended with him being winched into a Coast Guard helicopter shortly before the light faded.

Coast Guard Operations Specialist Lawrence Cumming said the 22-year-old surfer is “making progress” after his ordeal.

“He was conscious and breathing but severely hypothermic,” Mr. Cumming said. “Lifting a hypothermic person from the water is hazardous, but it was done successfully, and he was then taken to the nearest big hospital, which was in Belfast.”

The search was complicated because officials were only notified that Mr. Bryce was missing roughly 24 hours after the surfer entered the water, making it more difficult to predict his likely location.

“That meant it was a very, very large search area,” said Mr. Cumming. Lifeboats from Scotland and Northern Ireland scoured the waters as the helicopter searched from the air.

Mr. Bryce was spotted by the helicopter crew at about 7-30 p.m. on Monday shortly before the light started to give out.

“We were moving toward twilight and then darkness,” said Mr. Cumming.