"Those flat fish are all right," continued the coxswain. "I don't know about those skate. Rummy-lookin' creatures, ain't they, sir?" The deep bass hum of an aerial propeller attracted the crew's attention from the catch. Five hundred feet overhead was a coastal airship which had drifted down silently with her engines shut off, and, having just restarted her motors, was manoeuvring into the wind's eye. Perhaps it was as well that R.A.F. 1164 B carried on her fore-deck a square of canvas painted with the distinctive red, white, and blue circles. This device was a guarantee of her identity as a friend. Without it a small, grey-painted craft might easily be mistaken for a U-boat, with disastrous results. Then the engines were stopped again. Over the side of the nacelle a leather-helmeted and begoggled head appeared. The pilot, raising a megaphone to his lips, hailed: "R.A.F. launch ahoy! Any fish to spare us?" "Right-o!" shouted Derek in reply, but his voice was apparently inaudible to the airship's crew, for the hail was repeated. "Hold up some fish and let them see," ordered Derek. One of the men displayed the largest skate, a lozenge-shaped fish measuring more than a yard from fin to fin. "That's done them!" exclaimed Derek. But he was mistaken. Like a cormorant swooping down from a beacon, the huge and seemingly ungainly airship tilted her nose and dropped almost vertically until her nacelle was within fifty or sixty feet of the water. Then, with her propeller revolving at a reduced rate, she forged ahead on a similar course to that of the motor-boat. "By Jove! She's paying out her aerial. That's a smart move," announced Derek. "Easy ahead! Follow her up, coxswain." Rapidly the thin but strong wire was unwound until the end dangled within reach of the crew of the boat. In a trice one of the men grasped the wire and bent it round the tail of the skate. "Haul in!" shouted Derek. "Thanks, old man!" yelled the Blimp's pilot in reply. "When you've a chance, look us up at Netherton. We'll give you a joy-ride." "Sure thing!" replied Derek. "I'm on it!" The airship rose slowly, her crew still winding in the skate that was revolving rapidly at the end of the aerial; then, having gained possession of the novel catch, the Blimp bore swiftly southwards to resume her patrol, while No. 1164 B steadied on her helm and shaped a course back to the Bar Buoy. Happening to glance aft, Derek was somewhat surprised to find a small black kitten in the after-cockpit. "What's that animal doing on board?" he demanded. "Our mascot, sir," replied one of the men. "The Adjutant's dog chased it on board just before we left the pier." "No. 17 coming out, sir," reported the coxswain, pointing to a motor-craft that was approaching at high speed. Interest in the kitten was transferred to the oncoming boat. "She's signalling, sir," continued the coxswain, as a man holding a couple of hand-flags mounted the plunging fore-deck.