RICHARD WALKER / RWALKER@STARBULLETIN.COM Despite warning signs for Portuguese man-of-war, some people still ventured into the water yesterday at Ala Moana Beach.

Man-of-war swarm south-facing beaches on Oahu

No spineless, stinging sea creature was going to ruin Kaena Kekoa's afternoon dip.

Ignoring signs warning swimmers of an unusual Portuguese man-of-war invasion at Ala Moana Beach, the 15-year-old flung himself into the calm shallow waters and then triumphantly ran back to shore, where his buddies were laughing at his antics.

Kekoa wasn't stung in his short-lived swim.

But more than 35 others weren't as lucky yesterday after an influx of man-of-war on south-facing beaches. The jellyfish were brought in with moderate Kona winds, which were expected to shift to tradewinds overnight.

City Ocean Safety dispatcher Rob Miller said 25 people were stung in Waikiki, six at Ala Moana, three at Hanauma Bay and one at Sandy Beach by about noon yesterday.

At least one person was taken to the hospital after having a severe reaction to a sting, he said.

Warning signs were posted at all of the beaches, but few were deterred from going in the water. At Ala Moana Beach yesterday, some didn't even know about the man-of-war influx.

Instead of man-of-war, lifeguards were expecting to see a box jellyfish invasion yesterday. But none were spotted.

Man-of-war usually keep to Windward Oahu beaches, Miller said. But yesterday, he said, "the south was windward."

And "as long as the wind is blowing that way, the possibility remains" that the man-of-war could show up in south-facing beaches.

Man-of-war and box jellyfish have a similar sting, which can range from a minor irritation to excruciating pain. Lifeguards said those allergic to either creature should stay out of the water during an influx.