As it slowly moves in the shallow water along a beach, the robot splashes its fins like a small child playing in the surf. But the prototype device has a serious mission: destroying mines that could kill Marines and Navy SEALs as they come on shore. Such technology is considered the future of underwater bomb detection.

"It's a kamikaze vehicle, a suicidal robot," said Mathieu Kemp, a scientist with Durham, N.C.-based Nekton Research, LCC, which created the Transphibian.

The 3-foot-long device, which will some day carry 14 pounds of plastic explosives and attach itself to an underwater bomb before igniting, can be maneuvered by a joystick, which Kemp demonstrated last month at the Autonomous Underwater Vehicle Fest, an annual two-week gathering of researchers who design robots for military use.

Experts with the Panama City Beach-based Naval Surface Warfare Center say such robots eventually will replace minesweeping ships and perform dangerous jobs now done by specialized divers.

A 2003 mine-clearing operation in the port of Um Quasar, Iraq, was a major test for autonomous underwater vehicles. The technology helped the U.S. Navy clear a path for a British ship carrying 200 tons of food and emergency supplies. It took the AUVs about 16 hours to search nearly a square mile and help divers locate an undisclosed number of mines — a task the Navy says would have taken 21 days for divers working without the technology.

In the future, scientists plan to put explosives on the AUVs to destroy the mines. Meanwhile, they are using them to quickly and accurately differentiate ocean clutter from mines.

"The closer in you get to any port or harbor, the greater amount of clutter you will encounter — tires, rocks, coral reefs — there can be so much clutter you would not believe it," said Daniel Broadstreet, a spokesman for the Naval Surface Warfare Center, which specializes in neutralizing underwater mines.

"To screen out all that clutter is a huge job and it takes some very, very technologically advanced sensors," Broadstreet said.

The Um Quasar operation was a milestone for AUVs because it marked the first wartime use of the technology, said Tom Swean, team leader of the Office of Naval Research's Mine Warfare Science and Technology Program.

Swean joined the Office of Naval Research in Arlington, Va., in 1981, but his work took off in 1997 when the Navy SEALs got involved. They tailored the systems for missions including surveying the seabed, finding channels near the shore and locating mines.

"It was important that they have underwater vehicles that could not be seen very easily," Swean said. "Their missions are near shore and are very dangerous."

A decade later, wars in Iraq and Afghanistan have pushed advances in unmanned and robotic technology, especially on land and in the air where robots routinely inspect improvised explosive devices and drones conduct air reconnaissance.

"It's gone from zero to 60 pretty fast," said Jeffery Bradshaw, a scientist at the Pensacola-based Institute for Human and Machine Cognition, which is working with the warfare center on a project to use robots for port security.

The military is expected to spend more than $50 million on the acquisition of AUV technology in the next five years, Swean said. At the same time, more than $12 billion is expected to be spent on unmanned aircraft programs.

The next steps for the researchers include creating robots that function alongside troops as members of an operational team and ones that work with other robots.

"If one robot breaks or if one of the human team members is in trouble, they would know how to coordinate interactions — sort of like buddies," Bradshaw said.

Despite the interest in robotic technology, changes won't be immediate, Swean said. The Navy likely will phase out large mine sweepers, but it will need ships to deploy the robotic systems, he said.

Among the robots with the most promise is the Transphibian, which is still being developed.

"It's a good example of a hybrid concept, it can swim in the water and it can crawl on the sea floor," Swean said as he watched a prototype splash along the waters near Panama City Beach. "The last piece is to efficiently and cheaply go out to a real mine and place a charge on it."