There are two answers to this question; for there were two reasons for them not having recourse to the former alternative. The first was selfish; or rather, should we call it self-preservative. There was a doubt in the minds of all, as to their ability to reach the shore by swimming. It was a broad bay that had been seen before sundown; and once launched upon its bosom, it was a question whether any of them would have strength to cross it. Once launched upon its bosom there would be no getting back to the shoal water through which they were wading: the tidal current would prevent return. This consideration was backed by another, a lingering belief or hope that the tide might already have reached its highest, and would soon be on the "turn". This hope, though faint, exerted an influence on the waders, as yet sufficient to restrain them from becoming swimmers. But even after this could no longer have prevailed, even when the waves began to surge over, threatening at each fresh "sea" to scatter the shivering castaways and swallow them one by one, there was another thought that kept them together. It was a thought neither of self nor self-preservation, but a generous instinct, that even in that perilous crisis was stirring within their hearts. Instinct! No. It was a thought, an impulse if you will; but something higher than an instinct. Shall I declare it? Undoubtedly, I shall. Noble emotions should not be concealed; and the one which at that moment throbbed within the bosoms of the castaways, was truly noble. There were but three of them who felt it. The fourth could not: he could not swim! Surely the reader needs no further explanation? CHAPTER SEVEN. A COMPULSORY PARTING. One of the four castaways could not swim. Which one? You will expect to hear that it was one of the three midshipmen; and will be conjecturing whether it was Harry Blount, Terence O'Connor, or Colin Macpherson. My English boy-readers would scarce believe me, were I to say that it was Harry who was wanting in this useful accomplishment. Equally incredulous would be my Irish and Scotch constituency, were I to deny the possession of it to the representatives of their respective countries, Terence and Colin. Far be it from me to offend the natural _amour propre_ of my young readers; and in the present case I have no fact to record that would imply any national superiority or disadvantage. The castaway who could not swim was that peculiar hybrid, or _tribrid_, already described; who, for any characteristic he carried about him, might have been born either upon the banks of the Clyde, the Thames, or the Shannon! It was "Old Bill" who was deficient in natatory prowess--Old Bill, the sailor.