ABOARD THE HIGH SPEED VESSEL SWIFT (AP) - Drug smugglers who race across the Caribbean in speedboats will typically jettison their cargo when spotted by surveillance aircraft, hoping any chance of prosecuting them will vanish with the drugs sinking to the bottom of the sea.

That may be a less winning tactic in the future. The US Navy on Friday began testing two new aerial tools, borrowed from the battlefields of Afghanistan and Iraq, that officials say will make it easier to detect, track and videotape drug smugglers in action.

One of the devices on display aboard the High Speed Vessel Swift is a large, white balloon-like craft known as an aerostat, which is tethered up to 600 meters above the ship's stern.

The other tool on board for tests in the Florida Straits is a type of drone that can be launched by hand from the deck.

Together, they expand the ability of the Navy and Coast Guard personnel on board to see what's beyond their horizon, according to officials from both military branches and the contractors hoping to sell the devices to the US government.

The devices should allow authorities to detect and monitor suspected drug shipments from afar for longer sustained periods, giving them a better chance of stopping the smugglers. They also should allow them to make continuous videotapes that can be used in prosecutions.

"Being able to see them and watch what they are doing even before we get there is going to give us an edge," said Chief Chris Sinclair, assistant officer in charge of a law enforcement detachment on board the Swift, a private vessel leased to the Navy that is about to begin a month-long deployment to the south-western Caribbean, tracking the busy smuggling routes off Colombia and Honduras.

Crews practiced launching and operating both systems before a small contingent of media on board the Swift, managing to bring back video of vessels participating in a mock surveillance mission as well as radar and video images of the fishing charters and sailboats that dot the choppy seas separating Cuba from the US mainland.

The drone, officially a Puma All Environment unmanned aircraft system from Aerovironment Inc. of Simi Valley, California, splashed into the water on one landing and had to be retrieved. On the second round, it clacked noisily but intact on the shifting deck of the 321-foot ship. Rear Admiral Sinclair Harris, commander of the Navy's 4th Fleet, said the devices are necessary at a time when the service is making a transition to smaller, faster ships amid budget cuts.

The aerostat, formally the Aerostar TIF-25K and made by a division of Raven Industries Inc. of Sioux Falls, South Dakota, is filled with helium. It's an old technology, models of which have been used for decades, but it's packed with cameras and sensors that expand the ship's radar capability from about 5 miles (8 kms) to about 50 miles. That can help teams in an on-board control centre to identify larger ships, which now would appear as just dots on the horizon, from as far as 15 miles away.

The Puma, meanwhile, can be sent out to inspect a vessel flagged by the larger aerostat and give a "God's eye view," of what's happening on board, a job usually handled by a plane or helicopter, said Mr Craig Benson, director of business development for the company.

Both the aerostat and the drone have been used widely by the US government for overseas actions, but Adm. Harris and others aboard the Swift said neither has been used before by the Navy to conduct counter-drug operations.

Unmanned aerial devices, however, are not new to the drug fight. US Customs and Border Protection operates 10 Predator drones, including two based in Cape Canaveral, Florida, that patrol a wide swathe of the Caribbean through the Bahamas and down to south of Puerto Rico. It deployed one to the Dominican Republic last year for six weeks and has considered using one in Honduras. The others are used along the northern and southern borders of the United States.

The US military has long been deeply involved in counter-drug operations in the Southern Hemisphere, coordinated by a multi-agency task force based in Key West, Florida. Navy ships and Air Force jets use their radar to track and run down smugglers, though for legal reasons the actual arrests are carried out by the Coast Guard, civilian agencies or officials from other countries.

In March, the military said it would reduce patrols and sorties in Latin America and the Caribbean because of the automatic spending cuts imposed by Congress, another argument for increased use of aerial surveillance devices like the aerostat and drone, officials said.

Representatives on the Swift from both contractors declined to say what their systems cost. But they said each can be run at a fraction of the cost of the fixed-wing planes or helicopters usually dispatched to check out suspected smugglers.