Force reconnaissance Marines with 4th Force Reconnaissance Company sprint into the water with their F470 Combat Rubber Raiding Crafts in preparation for hydrographic reconnaissance training at Marine Corps Training Area Bellows in Waimanalo, Hawaii, Jan. 13. The training was part of a weeklong jump and dive training package that brought the unit, headquartered in Alameda, Calif., together with their Hawaii-based counterparts — 4th Force's 4th platoon. Following a real-life mission, the data they collect — such as the size and frequency of wave crests, sediment type and slope of the beach — allows unit commanders to determine what type of landing and vehicles the beach's composite supports, said Petty Officer 2nd Class Mike Weissman, a hospital corpsman with 2nd platoon, 4th Force.