The Utility Trawler is a Ship that is available at the Shipyard in Tech Level 1. Like an aquatic version of the Worker, it can gather Food from Fish and AquaHarvesters, and can build AquaHarvesters and Sensor Buoys. It has no attack.
"The Utility Trawler is a defenceless construction vehicle that doubles as a fishing boat. Besides gathering food from the sea, it may be used to create Aqua Harvesters, which are renewable aquatic food sources similar to Farms. Note the Gungan Utility Trawler may even construct underwater Prefab Shelters, for supplying Gungan forces."