Twenty people on a dolphin dive off of the Leeward Coast were stung as they surfaced into a field of jellyfish.

No one required medical attention.

Fifty-five people were stung in Waikiki over the last two days while 30 people were stung on the Leeward Coast today.

Lifeguards this morning counted 700 jellyfish up and down the Leeward Coast and 297 jellyfish in the Waikiki area, said Bryan Cheplic, spokesman for Honolulu Emergency Services.

"They haven't seen those numbers on the West side in 10 years," said Cheplic. "That's a lot for the West side, and we are advising people to stay out of the water."

Cheplic noted that typically fewer than one dozen jellyfish are found on the Leeward beach during influx periods, which occur about 10 days after a full moon.

About 120 jellyfish were found yesterday morning in the Waikiki area, when the advisory was issued.

The beaches in Waikiki, particularly in the water 'ewa of the Kapahulu groin, are the most commonly affected areas.

Other nearshore waters that may be affected include Hanauma Bay, Pokai Bay, Makaha Surfing Beach and Waimea Bay.

The city's Ocean Safety Division advises beachgoers, especially those allergic to the marine stings, to stay out of the water.

Anyone who is stung and experiences difficulty breathing, muscle cramps or spasms or persistent pain should seek immediate medical attention.