Capstone Turbine Corp. is targeting cargo ships using U.S. waterways as its next big growth area for its liquid natural gas micro-turbines, the company announced Wednesday. The Chatsworth manufacturer has chosen four distributors to go after marine customers on the U.S. eastern and western seaboards, and the Gulf coast; and two distributors for Europe. More than 2.5 billion tons of freight is transported annually in the U.S. so it is market that can use Capstone’s turbines to provide on-board electrical power for small- and mid-size commercial ships, said Capstone President and Chief Executive Darren Jamison. “The cost savings in reduced fuel and operational costs provide significant business benefits, while the low environmental impact is a vital, must-have element required by international governing organizations,” he said in a prepared statement.