battlecruiser squadron containing HMAS Australia, HMS New Zealand, Indomitable and Inflexible with their destroyers. After these came the 12th Submarine Flotilla and bringing up the rear were three battleships, which were accompanied by a number of screening destroyers. The initial speed was 16 knots, but Evan-Thomas had ordered his forces to increase speed to 22 knots when they passed May Island, which lay just at the entrance to the Forth estuary. All vessels were ordered to sail astern of each other, apart. To avoid attracting German U-boats, particularly as one was suspected to be in the area, after dark each vessel showed only a dim blue stern light accompanied by black-out shields that restricted the lights to one compass point either side of the boats' centre line, and they also were all instructed to maintain radio silence. The night was clear and the seas relatively calm, but the moon had not yet come up. As each group passed the Isle of May at the mouth of the firth, they altered course and increased speed to 20 knots. At approximately 19:00 hours, Courageous passed May Island and increased speed, just as a low-lying bank of mist settled over the sea. As the 13th Submarine Flotilla passed the island, a pair of lights (possibly minesweeping naval trawlers) were seen approaching the line of submarines. The flotilla altered course sharply to port to avoid them, but the helm of the third-in-line K14 jammed for six minutes and she veered out of line. Both K14 and the boat behind her, K12 turned on their navigation lights. Eventually K14's helm was freed and she tried to return to her position in the line. The next submarine in line, K22, had lost sight of the rest of the flotilla in the mist and veered off the line, with the result that she hit K14 at 19:17 hours, severing the bow and breaching the forward mess deck, where two men were killed. Both stricken submarines stopped and carefully pulled themselves apart whilst the rest of the flotilla, unaware of what had happened, continued out to sea. K22 radioed in code to the cruiser leading the flotilla to say that she could reach port but that K14 was crippled and sinking. About fifteen minutes later, the 2nd Battlecruiser Squadron passed the island and the two submarines. The captain of K22 ordered the firing of a red Very light,