The Coast Guard has joined the Honolulu Fire Department tonight in a search for a missing 20-year-old Swedish visitor who was swept out to sea off Waimea Bay.

Beachgoers reported Hannah Wanerskog had jumped off the rocks at Waimea Bay and got caught in the current.

The woman was last seen at 6:30 p.m. treading water, a fire official said.

The weather at about 9 p.m. was 17-mph northerly winds with 11-foot seas on top of 8-foot swells and heavy rain squalls, the Coast Guard said.

The Coast Guard launched its MH-65 Dolphin helicopter, its Cutter Ahi. An HC-130 Hercules plane will join the search at 11 p.m. tonight.

“We request all waterway users in the area to keep a sharp lookout for signs of distress and and to call 808-842-2600 with any information,” the Coast Guard said.

Off-duty Ocean Safety lifeguards are also assisting in the search.

The Fire Department dispatched seven units, including Air 1 and a rescue rig, to Waimea Bay Beach Park, located at 61-031 Kamehameha Highway.

HFD sent out a media notification at 6:59 p.m. The Coast Guard was notified at 7:35 p.m.

The Coast Guard issued an Urgent Marine Information Broadcast Notice to mariners. A police helicopter is assisting in the search.