MILWAUKEE HARBOR, LAKE MICHIGAN - The mast of a Coast Guard Station Milwaukee 45-foot Response Boat-Medium is the only thing visible as the boatcrew pilots it through the trough of a wave while conducting training near the entrance to Milwaukee Harbor in Lake Michigan Oct. 30, 2012.The crew took the RB-M, nearly 21 feet tall from the waterline to the tip of the mast, underway before storm conditions related to Hurricane Sandy fully impacted the Great Lakes, bringing on a sea state beyond the boat's operating limits.U.S. Coast Guard photo by Bruce Nason