Complex sentence: The Royal Marine operate two dedicated patrol vessels of the Island-class based at HMNB Clyde where they are primarily tasked with protecting high value Royal Navy ships such as the Vanguard-class submarines.
Split into simpler sentences: The Royal Marine operate two dedicated patrol vessels of the Island-class based at HMNB Clyde. There they are tasked with protecting high value Royal Navy ships such as the Vanguard-class submarines.