The naval escorts in the BATTLE OF THE ATLANTIC are now better equipped than ever before for hunting and destroying U-boats. While Asdic will detect a U-boat under water, escorts have two means of locating them on the surface. High-frequency direction-finding - or "Huff Duff" - detects a U-boat's radio transmissions and gives a bearing on it, while the Type 271 radio-location system can pinpoint the submarine up to forty miles. The conventional stern-launched depth-charge has now been joined by "Hedgehog", a launcher which throws depth charges forward over the bows. This means that the escort vessel can attack without losing Asdic contact as it does when it runs over the top of a submarine.