 In recent decades, commercial fishing vessels have been increasingly equipped with electronic aids, such as radio navigation aids and fish finders.During the Cold War, some countries fitted fishing trawlers with additional electronic gear so they could be used as spy ships to monitor the activities of other countries.Globally, the number of engine-powered vessels was estimated to be 2.8 million in 2016, this represents 61 percent of all fishing vessels, down from 64 percent in 2014, as the number of non-motorized vessels increased, probably because of improved estimations.