Serious crashes in the bustling Bay of Galveston have fallen to the lowest level in a decade even as more oil moves on U.S. waterways, official data show, suggesting that better training and equipment are helping avert spills like one in March. The number of crashes in the Texas bay, home to the Houston Ship Channel and the country's heaviest crude, fuel and chemical ship traffic, fell 68 percent to eight in 2013 from 25 in 2011, according to U.S. Coast Guard data obtained by Reuters through the Freedom of Information Act. But the March 22 crash of a Kirby Corp.