The yawl, having reached the brig, put three hands on board to navigate her into Yarmouth Harbour.  She stood back for the shore.  On passing the Newarp Floating Light, a signal was made requesting them to take a sick man on board, which they did, and then continued their cruise with a strong breeze, under three lugs.  They were taking a snack of food, when, having imprudently trimmed the ballast to windward--a most dangerous practice--a tremendous squall took the sails aback, and in a moment capsized her.  Brock being a good swimmer, struck out to get clear of his companions, his ears assailed by their cries, mingled with the hissing of water and the howling of the storm.  After a moment or so he swam back to help an old man to get hold of a spar; he then himself got on the boat, and stood upon its side; but finding that she was gradually settling down, he again struck off.  By this time he supposed that all his companions were lost; and he began to think of the awful position in which he was placed, the nearest land being fully six miles distant.  He remembered that it was half-past six just before the boat went over, and that as it was now low water, the tide would be setting off the shore, making to the southward, and that, therefore, he must swim fifteen miles before the ebb would assist him.  Just then, a rush horse-collar, which had served as a fender to the boat, floated by.  He got hold of it, and putting his left arm through it, was supported until he had cut the waistband of his cloth trousers, which then fell off.  He in a similar way got rid of his frock, his waistcoat, and neckcloth; but he dared not free himself from his oilskin trousers, fearing that his legs might become entangled.  He now put the collar over his head, but although it assisted him in floating, it retarded his swimming, and he had to abandon it.  He had gone some little distance, when he discovered one of his messmates swimming ahead of him.  The wind having gone down, no cries were heard, and the moon shone calmly on the water.  Ere long he beheld the last of his companions sink without struggle or cry. Should he give in also?  Not for a moment would he yield to such a thought; and he prepared himself for the desperate struggle.