A.—4

46

Danger ouif Areas. 12. When a vessel had been mined, or a moored mine was reported on the surface or swept up in a certain position, a dangerous area was declared with a radius of \\ miles round that position. During the war it was never found 'necessary to increase this radius of 1-| miles. 13. When a dangerous area was declared a wireless signal was sent to the destroyers on patrol, and to each of the W/T vessels at the adjacent control points, giving the new route which merchant vessels were ordered' to take, which was designated the route in force. It then became the duty of the Lieutenant in command of each of the control points to prevent any merchant ship passing until she had received the route in force. Boiler-cleaning, changing Water in Boilers, and Docking. 14. Boiler-cleaning was performed every thirteen weeks, with the aid of a squad of boiler boys, during which time the vessel was in the basin. The defects which, had occurred in the interval between last boiler-cleaning were made good, and the boiler-cleaning and repairs were completed in eight to ten days. During this period half the crew was sent on. eight days' leave. 15. Changing water : Water in the boilers was completely changed once in six weeks, or before if necessary, depending on the specific gravity of the water, a standard of which was fixed by the Engineer-Captain, Auxiliary Patrol. This change of water necessitated the trawler being in the basin for forty-eight hours. General Utility. 16. The trawlers on patrol, when fitted with depth charges, 7-5 in. howitzers, and (3-pr. high-angle gun, were most efficient protection for the merchant ships passing inshore to them or crossing the channel. When, the armament was complete no merchant vessel near the trawlers on patrol was ever attacked. It was very evident that the depth charges and howitzers were the weapons which the submarine feared, for when trawlers were only armed with 3-prs. several attacks were made. In addition, to the general protection of merchant shipping, the trawlers were always sent to investigate and destroy any British drifting mines sighted by men-of-war or merchant vessels in the patrol. 17. When a buoy broke adrift, or a derelict or floating wreckage dangerous to navigation was sighted, the trawlers were always sent to investigate, destroy, salve, or, if necessary, blow them up by means of guncotton. 18. For destruction of masts and wreckage, &c, the trawlers used tins of guncotton, 1,000 yards of cable, and a dynamite-exploder. 19. The trawlers on patrol were provided with charts showing the fishinglimits, and it was their duty to see that no trawlers or fishing-boats were outside these limits. If they were, their permits were collected and the vessels were sent to their respective home ports. Salvage. 20- When vessels were mined or collisions occurred trawlers went to their assistance, and if there was any possibility of salving every effort was made to do so. They were particularly clever in getting lines on board merchant vessels in heavy weather, and through their exertions a large number of vessels which had not been sufficiently injured to sink at once were brought safely into port.