There was no rifle in the lifeboat. In the Royal Navy they do things differently from the Mercantile Marine. Peter had an automatic. It was one of the things he took good care to provide himself with after his experiences in S.S. Donibristle; but the weapon was locked up in his cabin, and in the present circumstances it was like the Dutchman's anchor.
The boat was now a hundred yards from the life-buoy—the shark ten. The brute was still circling, sometimes diving, sometimes showing its head; but up to the present it had shown no sign of preparing to seize its prey by turning on its back.
A sudden inspiration flashed across Mostyn's mind. In the stern-sheets of the lifeboat was a box containing amongst other things a Verey's pistol. It was a weapon not of offence but for humane purposes. It was fired by means of a cartridge, but, instead of a bullet, it sent up a vivid coloured light to a height of about two hundred feet.
Peter stooped and opened the lid of the box. Thank Heaven! The pistol and cartridges were there. Deftly he opened the breech and thrust home the cardboard cylinder containing the detonator and explosive light; then, standing on the stern bench and steadying the tiller with one foot, he levelled the short-barrelled weapon.
For some seconds he waited. The shark in its orbit was immediately between the lifebuoy and the boat. Preston and his companion were in as much danger from the pistol as they were from the shark.
The huge fish dived and soon reappeared, this time well to the left of the buoy. It had partly turned on its back, and its wide-open jaws, triple lines of pointed teeth, and greenish-white belly were clearly visible, for by this time the whaler was less than twenty-five yards away.
It was now or never. The shark was preparing to make a dash for its victims under the bows of the boat.
Deliberately Peter pressed the trigger. He had to guess for elevation, knowing nothing of the trajectory of the missile. His aim was good. The rocket must have disappeared down the capacious maw of the shark, for there was no sign of the fiercely burning rocket sizzling on the surface. The satisfactory part of the business was that the shark disappeared and was seen no more.
Quickly the two men were hauled into the boat, both bordering on a state of collapse. Then, ordering the lascars to give way, Mostyn steered for the West Barbican, picking up the jettisoned lifebuoys on the way. He was one who always finished a job properly.