Armstrong promptly jumped overboard, to sink above his knees in the soft mud. Only by holding on to the gunwale was he able to keep himself from sinking still deeper.
"We can't land here," he announced. "We'll be in up to our necks."
"Must," declared Denbigh laconically, raising his voice to enable it to be heard above the now loud roar of the approaching bore.
Seizing the lead-line and bending one end round his waist Denbigh leapt overboard, threw himself at full length upon the mud, and working with his hands drew himself laboriously over the slimy surface. It was horribly exhausting work, but to his intense satisfaction he found himself making visible progress without sinking beyond a few inches in the ooze.
Ahead he could discern the dark outlines of the mangrove forest. It seemed an interminable distance away.
Presently his hand came in contact with the trunk of a tree, that had fallen and had been partly embedded in the mud. It afforded a precarious foothold, but proceeding carefully, Denbigh found that the farther end rested in comparatively firm soil.
Planting his feet against the trunk, the sub hauled at the lead-line with all his might. The flat-bottomed punt glided easily over the slime until its bows were within a yard of the fallen tree. Then, unexpectedly, the rope that had rendered such good service parted like pack-thread.
Denbigh, losing his balance, fell prostrate on the ground, which was here soft enough to break his fall but sufficiently stiff to prevent him from being swallowed up in the mud.
Quickly O'Hara and Armstrong jumped, and grasping their fallen comrade hauled him to his feet. They had barely time to gain the firm bank when the bore thundered past, sweeping the punt away like a straw. They had a momentary glimpse of its bows rearing high in the air on the crest of the foaming, breaking wall of water, then it vanished out of sight.
"Phew!" exclaimed Armstrong. "That was a narrow squeak."