JUST before sunset the Alerte entered the Chenal de Four, a dangerous and intricate passage between Ushant and the Brittany coast. Not only does the water on either side of the deep channel teem with jagged rocks—many of them submerged at various states of the tide—but both flood and ebb set at from six to seven knots, sometimes obliquely across the narrow passage. To complicate matters further, the rise and fall of the tide is twenty-four feet at springs and eighteen feet at neaps.
By taking advantage of certain states of the tides, a vessel bound for Brest and the Biscayan ports from the English Channel could save a long detour outside of Ushant by making use of the Four Passage, but, in any case, the utmost caution is necessary. Strangers are, in fact, warned that to attempt this channel without a pilot is entailing great risk.
To Captain Cain this hazardous locality presented no terrors. Many a time during his naval career he had taken submarines between Brest and Portsmouth, and had lurked in the Chenal de Four waiting to turn the tables on the U-boats that preyed on the shipping converging upon Ushant. Now he was going to put the knowledge that he had gained legitimately to a perfectly illegal use.
"Any sign of the Fairy, Mr. Pengelly?" he inquired.
"No sir."
"All right. I'll carry on. Quartermaster, keep those two towers in line—S. 5 E. is the course. Mr. Pengelly, see that the anchor is clear and fifty fathoms cable ranged on deck ready to let go."
The sun set in a vivid red sky. The lights of Kermorvan and St. Matthieu towers sent out their guiding beams. In a couple of hours the moon would rise.
Still the Alerte held on. Presently the lookout reported a sail on the starboard bow. Against the still strong afterglow in the western sky the intervening stretch of water appeared to be studded with rocky pinnacles.
"That's the Fairy," declared Captain Cain to Pengelly, who had rejoined him on the bridge. "She's brought up in four fathoms off Beniguet Island. No, we won't send out recognition signals.... Hard-a-port, Quartermaster.... Meet her!... At that!"
The Alerte, her speed reduced to five knots, appeared to be heading straight for a saw-like reef. Another alteration of helm and she slipped past within half a cable's length of this ridge of rocks, eeled her way between two half-tide rocks and settled down on a course S.S.W.