A 16-year-old boy disappeared Tuesday night while swimming in the ocean just off Cannon Beach.

The U.S. Coast Guard was brought in to help search for Elliot Hearing, of Seaside, but as of early Wednesday morning, he had not been found and was feared drowned.

Searchers said there was a riptide in the area that likely pulled Hearing out to sea. Friends said they saw him struggling and tried to help, but he slipped away.

Crews on board a helicopter and also on a 47-foot life boat resumed the search at first light Wednesday morning but it was called off around 10 a.m., after they failed to find any sign of the boy.

Hearing was a student at Seaside High School. Counselors were on hand in the school library Tuesday, to help friends and family members.

Earlier Tuesday, two people were rescued after being pulled out into the surf by a riptide near Seaside. The Coast Guard also rescued two people in the ocean off Warrenton and Tillamook.

What is a riptide?

Riptides are strong currents of water that rush out to sea, and may appear as dark, choppy water. Officials say strong tides are producing conditions that expose swimmers and waders to dangerous rip currents along the Oregon Coast.

Experts said anyone who spots debris and foam floating out to sea should know that it could be the result of a nearby rip current.

What to do if you get caught in riptide

Anyone who gets caught in a rip current should swim parallel to the shore until out of it, then swim at an angle back to shore. People who can't swim should tread water and wave or call for help.

A rip current can form anywhere. But they seem to have become especially common north of Tillamook Head during the past week, so visitors were urged to take special care when visiting that area.