The footmarks of the three mids were still easily traceable, even on the ground already trampled by the Arabs, their horses, and maherries. The "cloots" of a camel would not have been more conspicuous in the mud of an English road, than were the shoe-prints of the three young seamen in the sands of the Saara. The Arab trackers had no difficulty in making them out; and in a few minutes had traced them from the mouth of the gorge almost in a direct line to the sea. There, however, there was a breadth of wet sea-beach, where the springy sand instantly obliterated any foot-mark that might be made upon it, and there the tracks ended. But why should they have extended farther? No one could have gone beyond that point, without either walking straight into the water, or keeping along the strip of sea-beach, upwards or downwards. The fugitives could not have escaped in either way, unless they had taken to the water and committed suicide by drowning themselves. Up the coast or down it they would have been seen to a certainty. Their pursuers, clustering around the place where the tracks terminated, were no wiser than ever. Some of them were ready to believe that drowning had been the fate of the castaways upon their coast, and so stated it to their companions. But they spoke only conjectures, and in tones that told them, like the rest, to be under the influence of some superstitious fear. Despite their confidence in the protection of their boasted Prophet, they felt a natural dread of that wilderness of waters, less known to them than the wilderness of sand. Ere long they withdrew from its presence; and betook themselves back to their encampment, under a half belief that the three individuals seen and pursued had either drowned themselves in the great deep, or by some mysterious means known to these strange men of the sea, had escaped across its far-reaching waters. CHAPTER THIRTY. A DOUBLE PREDICAMENT. Short time as their pursuers had stayed upon the strand, it seemed an age to the submerged midshipmen. On first placing themselves in position, they had chosen a spot where, with their knees resting upon the bottom, they could just hold their chins above water. This would enable them to hold their ground without any great difficulty, and for some time they so maintained it. Soon, however, they began to perceive that the water was rising around them--a circumstance easily explained by the influx of the tide. The rise was slow and gradual, but for all that they saw that should they require to remain in their place of concealment for any length of time, drowning must be their inevitable destiny. A means of avoiding this soon presented itself. Inside the line of breakers, the water shoaled gradually towards the shore. By advancing in this direction they could still keep to the same depth. This course they adopted, gliding cautiously forward upon their knees whenever the tide admonished them to repeat the manoeuvre.