Navy divers conducted an underwater survey off the Wai'anae Coast on Wednesday in search of more of the kind of propellant charges that have washed up on shore, but only found one, officials said.

The Army, which has the lead in the investigation of the propellant, said efforts will continue to locate and identify the source of the munitions.

The results of a Defense Department survey of munitions dumped in relatively shallow waters off the coast are expected to be released next week, meanwhile, and could lead to a cleanup.

Hundreds of the low-explosive propellant charges, likely the kind used to fire high-explosive rounds from large-bore guns, have been collected by Wai'anae Coast residents in recent weeks.

The Army preliminarily identified the explosive as single-base nitrocellulose. Included in the same group are smokeless gunpowders and flares. The 1-inch olive, brown and yellow propellant charges, also called grains, have been washing up on Wai'anae Coast beaches for decades.

Cameron Guadiz, an assistant dive instructor with Captain Bruce Scuba Charters who dives regularly off the coast, showed military officials dive spots where he's seen the propellant before.

The location where Navy divers searched in 45 feet of water was likely a dive site called Five-Inch Reef about three-quarters of a mile offshore from the sewage treatment plant, Guadiz said.

Another location where the propellant has been found is called Ammo Reef and is about 200 yards from the Wai'anae boat harbor.

The Army said the Navy divers "experienced significant underwater currents" when they went out on Wednesday. It was unclear if they will head out again to find the propellant.

At the request of the Defense Department, the National Oceanic and Atmospheric Administration, the state Department of Land and Natural Resources, and the University of Hawai'i surveyed 5 square nautical miles off the Wai'anae Coast last June for old munitions.

A NOAA official recently said the propellant charges were not identified in the sweep.

The marine researchers also collected water, fish and sediment samples to compare with sites without munitions. A U.S. Army Corps of Engineers survey in 2002 identified more than 2,000 military munitions dumped off Wai'anae.

Reach William Cole at wcole@honoluluadvertiser.com.