HAWAI'I KAI — City Ocean Safety officials are troubled by recent vandalism — spray painting and removal of key letters — on the 5-foot-tall monument prominently standing in the middle of the access to the China Walls cliff area in Portlock.

Visitors also wonder how effective the white monument, called an obelisk, is for what it was designed to do: warn visitors that drownings occur and ocean waves can sweep people into the sea.

Traditional written warning signs often go unheeded, which prompted city Ocean Safety officials eight months ago to erect the tall, white Washington Monument-looking sign with English and Japanese text. Two more obelisks — an internationally recognizable symbol of danger commonly used by Japanese fishermen — are being built, one for the Lana'i Lookout and another at Spitting Caves.

The monument was damaged once before with black marking pens, said lifeguard Capt. Kevin Allen. But the recent vandals have loosened the obelisk's foundation and removed letters spelling out the word drownings. Now on one side the warning says "rowings have occurred." A cropping of lava rocks holds it upright.

Allen, who painted over the markings as soon as he learned about them, said he will go out to China Walls and work on getting the monument on firmer ground. Lifeguards plan to keep installing the monuments wherever needed.

"If it keeps just one person from drowning, then we've done our job," Allen said.

When the monument first went in, Hawai'i Kai resident Ekahi Sillas took a good look at it. A regular at the cliff-jumping surf spot, Sillas said many people will ignore warnings on regular flat signs, and the white obelisk monument is a good reminder to be wary of the ocean.

Sillas knows that people can get into trouble and that some have died out at China Walls.

A Portlock Task Force made up of firefighters, lifeguards and emergency medical services workers reported that there were an average of three drownings a year over the past five years at China Walls and nearby Spitting Caves, another popular sea-cliff area.

"It's better than nothing," Sillas said. "When I brought my friends from California here, they asked what it was. I come here all the time. I know about the currents and the conditions."

The area has been popularized by Internet blogs and travel guides but does not have any lifeguards on site and is in the middle of a residential area.

Traum Lewin, a regular sea-cliff surfer, said he's glad the lifeguards have erected the obelisk for newcomers who don't know how to time the waves before jumping from the cliff into the ocean 10 feet below.

"I don't surf by the wall," Lewin said. "I surf outside. I've seen people get hurt out here."

Robby Webb, another regular to the break, was angered by the vandalism and the lack of respect it showed to the lifeguards who are trying to save lives.

"Surfing can cause a lot of people to get hurt," Webb said. "It's a dangerous break. I think the vandalism was done by people who are bored and they just play around with things and are not respectful."

Reach Suzanne Roig at sroig@honoluluadvertiser.com.