A U.S. Marine from the 26th Marine Expeditionary Unit jumps into the water from a CH-46E Sea Knight helicopter during helocast exercises off the coast of Vieques Island, Puerto Rico, on Jan. 20, 1998, for Joint Task Force Exercise 98-1. More than 30,000 U.S. military personnel are participating in the exercise which is testing joint forces on their ability to deploy rapidly and conduct joint operations during a crisis. All branches of the armed forces are training side-by-side using the latest advances in technology in a simulated high-threat environment that involves air, naval and ground operations. The 26th Marine Expeditionary Unit is from Camp Lejeune, N.C.