Illustration by Stephen Rountree

One of the Navy´s most advanced training systems, VAST uses computers that create a virtual island (or any other venue), based on photography of actual locations. Though military personnel involved in the exercise will see the island on their computer screens, their actual target is cordoned off by up to five sonar buoys far out at sea. These buoys pinpoint ordnance hits, calculate where they would have struck the island and provide smoke and explosions to signal the impacts. A predator drone is used to provide a simulated view of the target area. 1. Destroyer
2. Virtual airburst to illuminate area
3. Predator drone
4. Virtual hit
5. Sonar buoy

A marine forward observer finds the target with his binoculars. He radios the coordinates to a Navy gunner aboard a destroyer, who fires a 5-inch shell toward an enemy weapons depot–located just outside a small island’s largest city. The projectile flies 12 miles and scores a direct hit. The marine observer watches the explosion and radios a confirmation back to the ship. Then it’s on to the next target: enemy headquarters.

Welcome to Virtual At-Sea Training (VAST), in which the shots are real but neither the target nor the island actually exist.

Digitally rendered virtual targets on computer screens offer the marine, the gunner and other military personnel the experience of shooting at real targets without the costs of doing so. Though in development for years, VAST was accelerated in 2002 after the Navy decided to find an alternative to Vieques, the Puerto Rican island that aircraft carrier battle groups have practiced bombing for nearly half a century. Local protests there have been a public relations disaster for the service, rippling back to cities with large Puerto Rican populations like New York.

Last November, the Navy conducted a successful full test of the system in the Gulf of Mexico. “In many ways, VAST is really an improvement over Vieques,” says Michael Dunaway of the Office of Naval Research in Arlington, Virginia. “Not only are VAST exercises cheaper, we can set them up wherever we want without transporting equipment and personnel long distances.” He adds that most munitions used nowadays are fired from very long ranges, so seeing a real hit isn’t always necessary. Vieques and other land-based ranges, where a stray shot could result in catastrophe, are too small for guided missiles anyway.

VAST´s virtual environments are created with photography-based digital imagery, viewed as video feeds. When a round strikes the water in the target area, GPS-equipped sonar buoys can pinpoint its location. VAST’s computers, which have the coordinates and topography of the virtual island, then trace the round´s trajectory back to where it would have passed through the island’s surface. Forward observers–who might actually be at bases thousands of miles away–then see a realistic explosion or puff of smoke to signal the impact.

A VAST target area may be as wide as 3,000 yards across and can be established almost anywhere at sea. Eventually, the U.S. military will use the system to hold joint operations with other services or foreign allies, who can participate through computer linkups, without even leaving their bases. (In fact, the system also permits exercises to take place without any live firings at all–they’re only necessary when weapons crews are being trained.) Though VAST can simulate such factors as crosswinds, fog, daylight and obscured vision, it is not yet a complete substitute for real-world training. The Navy will continue to conduct live-fire training at its other bombing ranges in Hawaii, Florida and other locales.