The yacht was motionless, and the water round her visibly lower. Petulant waves slapped against her sides, but, scattered as my senses were, I realised that there was no vestige of danger. Round us the whole face of the waters was changing from moment to moment, whitening in some places, yellowing in others, where breadths of sand began to be exposed. Close on our right the channel we had left began to look like a turbid little river; and I understood why our progress had been so slow when I saw its current racing back to meet the Elbe. Davies was already below, laying out a more than usually elaborate lunch, in high content of mind. “Lies quiet, doesn’t she?” he remarked. “If you _do_ want a sit-down lunch, there’s nothing like running aground for it. And, anyhow, we’re as handy for work here as anywhere else. You’ll see.” Like most landsmen I had a wholesome prejudice against running aground, so that my mentor’s turn for breezy paradox was at first rather exasperating. After lunch the large-scale chart of the estuaries was brought down, and we pored over it together, mapping out work for the next few days. There is no need to tire the general reader with its intricacies, nor is there space to reproduce it for the benefit of the instructed reader. For both classes the general map should be sufficient, taken with the large-scale fragment _[See Chart A]_ which gives a fair example of the region in detail. It will be seen that the three broad fairways of the Jade, Weser, and Elbe split up the sands into two main groups. The westernmost of these is symmetrical in outline, an acute-angled triangle, very like a sharp steel-shod pike, if you imagine the peninsula from which it springs to be the wooden haft. The other is a huge congeries of banks, its base resting on the Hanover coast, two of its sides tolerably clean and even, and the third, that facing the north-west, ribboned and lacerated by the fury of the sea, which has eaten out deep cavities and struck hungry tentacles far into the interior. The whole resembles an inverted E, or, better still, a rude fork, on whose three deadly prongs, the Scharhorn Reef, the Knecht Sand, and the Tegeler Flat, as on the no less deadly point of the pike, many a good ship splinters herself in northerly gales. Following this simile, the Hohenhörn bank, where Davies was wrecked, is one of those that lie between the upper and middle prongs. Our business was to explore the Pike and the Fork and the channels which ramify through them. I use the general word “channel”, but in fact they differ widely in character, and are called in German by various names: Balje, Gat, Loch, Diep, Rinne. For my purpose I need only divide them into two sorts—those which have water in them at all states of the tide, and those which have not, which dry off, that is, either wholly or partly at low-tide.