The Assault Barque is a naval vessel designed and used by the Locust Horde to transport troops and equipment to land on a hostile or potentially hostile shore. The Barque takes its propulsion from a Reaver which is fused to the hull of the vessel and its mechanism, similar to that of the Siegebeast. When the Barque opens, it releases a cloud of ink for yet unknown reasons, though this might be the fuel source of the boat.
When the Gears tried to leave the island, a large group Barques landed several Locust on the shore that laid siege to the island until they were fended off. The Gears then used a Barque that they hijacked to return to Halvo Bay so that they could launch the missile on Karn. They left the hijacked Assault Barque stationed at a channel near the Wharf District. It is unknown how the Gears managed to operate the vessel.
The Assault Barques were not seen again by COG forces, or at least no encounter has been mentioned, and they were presumably replaced by Locust Gunboats for yet unknown reasons, although it could be that the Gunboats could carry weapons and were faster than the Assault Barques which were designed for breaching heavily fortified areas by transporting troops.
Behind the scenes
The name of this vehicle is never given in game, however data name for it in ''Gears of War: Judgment'' comes up as Barque.
The data files of Gears of War: Judgment also state that the creature that propels the vessel at the end of the Barque is a Reaver.