So far, nothing had been seen or heard of the _Raven_, but a strict watch was kept each day for the Hankers' vessel. But one more stop was to be made, at the island of San Murio, and then the _Swallow_ was to proceed directly for the locality where the treasure ship _Happy Hour_ had gone down. Day after day passed and nothing of importance occurred. One afternoon there was some slight break in the machinery and the ship had to come to a stop for a couple of hours while repairs were being made. It was a hot day and several of the sailors readily obtained permission to go in swimming. "I think I will join them," said Dave to his father. "The water looks cool and tempting." "All right, Dave," was the answer. "But take care you don't get a cramp." "If I do, you can bet I'll yell for help," laughed the young diver. He was soon in the water and sporting around to his heart's content. The sailors had allowed one of the small boats to drift astern, and Dave swam to this and showed several of them how to make deep dives and long stretches under the ocean's surface. The party were in the midst of having a lot of fun when a thrilling cry came from the ship. "A shark! A shark! Beware of the shark!" All gazed in the direction pointed out, and saw a huge shark approaching rapidly, as if prepared to devour one or another of them! CHAPTER VI STRUCK BY LIGHTNING "We will be devoured!" "Swim for the ship, boys!" "See, he is coming this way!" "Save me, somebody! Save me!" Such were some of the cries which rang out as the sailors swam, terror-stricken, in one direction or another. In the meantime the shark came on rapidly. He was a big creature, with a cruel-looking mouth and teeth that were equally ugly. At first he turned toward one of the sailors, who was swimming for the ship. But a rope was thrown to the tar, and this he grasped and was hauled on board with all rapidity. Then the shark turned for another of the sailors. But this fellow was making for the small boat, and soon he was on board and safe for the time being. Then the shark turned swiftly and came for Dave. The youth dove at once, remembering that a shark can attack under water only with difficulty. But the boy could not remain under the surface forever, and at last he had to come up, this time somewhat closer to the _Swallow_. But the shark saw him and turned again to attack the young diver. It was a critical moment, and Dave was about to give himself up for lost when a shot rang out, followed by another. Amos Fearless had been in the cabin when the shout of "Shark!" was raised. Knowing at once the peril of the situation, he had caught a gun from the cabin wall and lost no time in hurrying to the deck. The shark was still ten feet away from Dave when Mr. Fearless fired. The first bullet struck the monster in the side, doing little damage.