Emergency services are searching a “huge area” of coastline in the hope of finding an angler swept out to sea in the Mearns.
The man was night fishing on the foreshore at Tangle Ha, a tiny community north of St Cyrus, when he disappeared.
It is understood the man was out with another angler, who reported his companion missing at 3am on Sunday.
Four rescue teams are co-ordinating with a Rescue Bond 1 helicopter and Montrose lifeboat, which is engaged in search some distance from the coast.
Ross Greenhill from the Marine Coastguard Authority told The Courier: “We have had four rescue teams, a helicopter and a boat out.
“We are in a search pattern at the moment, really looking from St Cyrus to just outside Johnshaven, which is a vast area to search.”
The stretch of coast between Gourdon and Easthaven is a fertile area for catching cod in winter, and anglers come from all over Scotland to fish there.
A coastguard spokeswoman described sea conditions as “exceedingly rough”.
Several police vans are parked in the village, where people expressed concern for the missing man.
Kevin Brown, watch manager at Aberdeen coastguard, said: “A search is still ongoing this morning to find this missing sea angler. Weather conditions are improving and although the wind in the early hours was gusting force 4 (13-17mph), there was a large sea swell of 2-3 metres.
“We’d always recommend that anglers check weather and tides before setting out and make sure they wear suitable clothing and a lifejacket.
“If you get into difficulty, or spot someone else in trouble, call 999 straight away and ask for the coastguard.”
For the latest, see Monday’s Courier.