A group of Big Island divers hopes to sink a retired Navy ship in waters off the Kona coast to serve as an artificial reef and a lure for divers that may help take some diving pressure off natural reefs.

The West Hawai'i Artificial Reef Foundation has its eye on a 511-foot Navy ammunition ship, the USS Mauna Kea, which is now moored in a reserve fleet yard in California, said WHARF board member Rick Decker.

"There's a certain mystique about diving a wreck, and divers love it," Decker said.

Kona-based ocean advocate Rick Gaffney said he is generally in support of such artificial reefs, but worries about their environmental impact.

"I like the concept of having a wreck here. It takes the (diving) industry off the reefs. But I have reservations about the long-term impacts of creating a new ecosystem where none previously existed," Gaffney said. "Corals and algae will affix themselves to it, and it'll build a whole ecosystem. I'm not sure we understand the impacts of that."

Several wrecks off Honolulu are used for dive tours, and the longtime Lahaina scenic attraction, the Carthaginian II, was sunk Dec. 13 off Puamana, West Maui, to be used as an artificial reef and diving attraction.

The Carthaginian sinking was arranged by Atlantis Adventures, a submarine tour company that also has put wrecks on the bottom off O'ahu. However, WHARF is not directly associated with any commercial dive operation, and would not own the wreck, Decker said. The state would own and control it.

"We just dive wrecks, and we would like to have a wreck to dive," Decker said of his motivation.

The group has completed a draft environmental impact statement and is soliciting public comment. Decker said he hopes to have the wreck in place off Kona in about two years.

The ship would be thoroughly cleaned to avoid pollutants leaking from the wreck.

The group proposes to sink the ship onto a sandy bottom about a half-mile from shore off Pa'ao'ao Bay, which is about 8 miles south of Kailua and 2 miles south of Keauhou. The water there is 110 to 120 feet deep.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.