It was slow work, but every stroke carried us farther away from the shoal and nearer the shore, till at last the shooting died down, and when the moon did come out we were too far away to be in danger. Not long afterward we answered a shoreward hail, and two Whitehall boats, each pulled by three pairs of oars, darted up to us. Charley's welcome face bent over to us, and he gripped us by the hands while he cried, "Oh, you joys! You joys! Both of you!" When the flotilla had been landed, Nicholas and I and a watchman rowed out in one of the Whitehalls, with Charley in the stern-sheets. Two other Whitehalls followed us, and as the moon now shone brightly, we easily made out the oyster pirates on their lonely shoal. As we drew closer, they fired a rattling volley from their revolvers, and we promptly retreated beyond range. "Lot of time," Charley said. "The flood is setting in fast, and by the time it's up to their necks there won't be any fight left in them." So we lay on our oars and waited for the tide to do its work. This was the predicament of the pirates: because of the big run-out, the tide was now rushing back like a mill-race, and it was impossible for the strongest swimmer in the world to make against it the three miles to the sloops. Between the pirates and the shore were we, precluding escape in that direction. On the other hand, the water was rising rapidly over the shoals, and it was only a question of a few hours when it would be over their heads. It was beautifully calm, and in the brilliant white moonlight we watched them through our night glasses and told Charley of the voyage of the _Coal Tar Maggie_. One o'clock came, and two o'clock, and the pirates were clustering on the highest shoal, waist-deep in water. "Now this illustrates the value of imagination," Charley was saying. "Taft has been trying for years to get them, but he went at it with bull strength and failed. Now we used our heads...." Just then I heard a scarcely audible gurgle of water, and holding up my hand for silence, I turned and pointed to a ripple slowly widening out in a growing circle. It was not more than fifty feet from us. We kept perfectly quiet and waited. After a minute the water broke six feet away, and a black head and white shoulder showed in the moonlight. With a snort of surprise and of suddenly expelled breath, the head and shoulder went down. We pulled ahead several strokes and drifted with the current. Four pairs of eyes searched the surface of the water, but never another ripple showed, and never another glimpse did we catch of the black head and white shoulder. "It's the Porpoise," Nicholas said. "It would take broad daylight for us to catch him."