had already arisen between him
and the boatswain as to who could send up the most oysters--while I
stood in the main chains, tending the signal line and intently watching
the toiling figure diligently shovelling oysters away down below in the
cool green shadow of the schooner's hull. As on the previous day, we
had a man aloft for the express purpose of keeping a lookout for sharks,
but every time we hailed him his reply was that there were no sharks in
sight.

Suddenly, as I stood watching Cunningham, a great greyish-brown object
slid lazily along beneath me, and paused immediately above the toiling
diver. A single glance sufficed me to identify it as a shark, full
twenty feet in length; and I instantly sent down the pre-arranged danger
signal, while the man at the masthead yelled: "Shark ho! right over the
diver!" I sang out to the two men who were in the boat receiving the
oysters as they came up to seize a couple of oars and violently splash
the surface of the water with them, in the hope that the sound would
drive the brute away--for, after all, the shark, voracious as it is, is
a timid creature, easily frightened by any sudden or unaccustomed noise.
And the attempt met with at least partial success, for the shark
instantly darted away a few yards; but it as suddenly turned, and,
apparently quite undismayed by the splashing, slowly came back.

Meanwhile, however, Cunningham had dropped his shovel, and, having drawn
the sword bayonet with which he was armed, stood quite quietly on the
defensive, alertly on the watch. Evidently the shark did not quite know
what to make of the strange creature on the sea bottom, for he now began
to swim rapidly to and fro, making short tacks each way of a few yards
only, eyeing Cunningham intently all the while. Then, before we could
do anything in the nature of intervention, the brute suddenly wheeled
and made a dash straight for the engineer. So lightning swift was the
onslaught that the only thing I distinctly saw was the quick whisk of
the creature's tail as it turned, and the sudden dart of the great body,
followed by an equally sudden writhing movement; then in an instant the
great fish appeared to be enveloped in a cloud of red, in which it
almost disappeared; and the next thing I distinctly realised was that it
was gone, while, the red cloud slowly dissipating, Cunningham was
presently revealed in the very act of recovering his shovel for the
purpose of resuming work.