Complex sentence: The wrecks of the and the dreadnought, which exploded at anchor during the First World War, are war graves protected under the Protection of Military Remains Act 1986, only divers of the British armed forces are permitted to visit them.
Split into simpler sentences: The wrecks of the and the dreadnought, which exploded at anchor during the First World War, are war graves. Only divers of the British armed forces are permitted to visit them.