A city Ocean Safety Officer today patrols Waikiki Beach by the Kapahulu Groin, one of the most common areas where box jellyfish are spotted. RICHARD AMBO | The Honolulu Advertiser

An advisory has been issued for today and tomorrow.

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

Other near-shore waters that may be affected include Hanauma Bay, Poka'i 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.