In this screenshot, it's a bit different. It's the cutter vessel, right ?
Well the cutter vessel has no bow thruster, she has an additionnel azimuth engine in the front. This is an additionnal engine you can turn at 360°, you can use for precise manoeuvers, and to sail at low speeds.
This is described in the in-game description of the ship :
This Coast Guard 378-ft cutter is powered by a CODOG propulsion consisting of 2 Pratt&Whitney gas turbines of 36000hp together, or 12 cylinder diesel engines developing 7000hp along CP propellers. An orientable bow thruster can move the ship up to a speed around 5 kt. To fulfil her missions, she has an important range and a high endurance, enabling her law enforcement and flag showing abroad.