liquid compass.

"Twelve degrees out, at least," exclaimed Detroit.

"And goodness only knows how long it has been like that. Perhaps before the yacht was hove-to perhaps even when we passed Norderney Gat."

"Well, we've a good offing, so there's little harm done. The wind is falling some, and if only this tarnation rain would quit——"

"What's that?" interrupted Hamerton, holding up his hand.

"Nothing, I guess," replied Detroit, after a few moments. "What's the matter with your nerves?"

"There's nothing the matter with my nerves," asserted the Sub with asperity. "Feel my pulse. But I could swear I heard a fellow calling out, 'Who goes there?' in German."

Detroit chuckled.

"Guess I'll have to take your word for it," he said. "I'll git. It's time I made some coffee."

The Sub watched his companion descend into the cosy cabin and strip off his glistening oilskins. Then, to avoid the glare, he closed the sliding hatch, and peered steadfastly into the mirky night.

The rain was coming down with torrential violence. The wind had died utterly away, and the saturated sails were slatting violently from side to side with the motion of the craft.

Beyond the patter of the heavy raindrops, no sound came from the black vault that encompassed the Diomeda on every side.

"If only I could pick up a light!" he muttered; then, mainly with the idea of doing something, he picked up the coiled lead-line.

"Five fathoms, by Jupiter!" he exclaimed; then, seized by an inspiration, he dived into the cabin and bent over the chart. According to the course the minimum depth ought to be thirteen.

"We've muddled the whole show, Oswald," he announced. "We're inside the five-fathom line, and that means we are only a few miles from shore. I'll put her due west, and see what comes of that. There's enough wind now to give her steerage way."

"Couldn't do better," replied Detroit laconically, "unless it's to have some coffee and a few rusks. I'll be slick about it."

Hamerton returned to his rain-exposed post, put the little craft's head in the desired position, and waited. Five minutes later he made another sounding. This time it was four and a half fathoms.

"I'll carry on," he resolved. "It may be a slight irregularity in the ground, although the general tendency is for it to deepen."

Four fathoms—three and a half.

"Say, ready for your coffee?" asked Detroit, holding a cup in his extended hand through the partially open hatchway.

"Far from it," replied the Sub. "Come on deck and give a hand to put her about. The water's shoaling rapidly."

"How's her head?"

"Nor'-nor'-west. I'll keep her at due south for a bit until we find deeper water."

Slowly the Diomeda came into the wind and paid off on the other tack. As she did so Hamerton noticed that, in spite of the heavy rain, the seas were steeper, and showed a decided tendency to break.

"Guess that's surf," said the American, as the dull rumble of a heavy ground swell was heard above the hiss of the rain. "Dead ahead, too."

Hamerton heard it also. The Diomeda was making straight towards a sandbank. Unhesitatingly he put the helm hard up. He would not risk going about; he chose the lesser danger of gybing all standing.

With a thud the boom swung over, and the stanch little craft drew away from the hidden danger. Her course was now nor'-west.

"Still shallow," announced the Sub. "It's less than four fathoms, but the water seems calmer."

"Light ahead!" shouted Detroit. "Showing red and white. We're right on the dividing line between the two sectors."

"I see it now," replied Hamerton, as he altered his helm to bring the Diomeda more into the arc of the white light. "Hanged if I know what or where it is, but, by Jove, there's a crowd of lights beyond!"

Through the rain a multitude of yellowish lamps blinked after the manner of a street, except that, instead of two rows, there were four or five. The water, too, was almost calm, ruffled by a faint breeze that contrasted vividly with the strong wind but a few hundred yards astern.

The Sub's ready wit grasped the situation. Unknowingly the yacht had entered an anchorage, for the lights represented the anchor lamps of a number of vessels.

"This is good enough for us," he exclaimed. "We'll bring up here till daylight. I shouldn't wonder if we're off the mouth of the Jade or the Weser. Stand by and let go, old man. I'll bring her up into the wind."

Two minutes later the rattling of the chain cable announced the fact that Detroit had let go the anchor. The saturated sails were quickly lowered and stowed, the navigation lights removed, and an anchor lamp hung from the fore stay.

A final look round satisfied Hamerton that he had done all that was humanly possible. The Diomeda was riding snugly in a safe but unknown anchorage.

"Watch below, all hands!" he exclaimed cheerily. "We'll sleep like logs. To-morrow, my dear Detroit, we'll wake up and find ourselves close to a picturesque little German village, and you can go ashore and buy fresh milk and new rolls. Think of that, and dream on it, old man."

Detroit merely nodded. He was already half-asleep. Before the Sub was ready to turn in, his companion was breathing heavily. Five minutes later the crew of the Diomeda were fast asleep, heedless of the peril that overshadowed them.

CHAPTER IV

Arrested

The bump of some heavy object against the yacht's side caused both sleepers to wake simultaneously. It was day; a dull light filtered through the skylight, though not strong enough to be caused by the sun. The Diomeda was rocking sluggishly in the slight swell as she rode to her cable.

"Eight o'clock, by Jove!" exclaimed Hamerton drowsily; "and drizzling with rain, I fancy. What was that noise?"

"We won't find out by lying here," said Detroit, setting the example by springing out of his cot. As he did so came the unmistakable sound of a boathook engaging the little craft's rigging screws, and a peremptory voice hailed in German.

"Custom-house people. They're early," announced the Sub. "It won't do to keep those gentlemen waiting, so I will interview them in my pyjamas."

Pulling back the sliding hatch, and pushing open the half-doors, Hamerton went on deck. Lying alongside was a grey cutter manned by seamen whose cap ribbons and blue-and-white jerseys, showing between the V-shaped opening of their jumpers, betokened them to be man-o'-warsmen of the Kaiser's navy. In the stern sheets sat two fair-haired officers—their chief characteristics fiercely upturned moustaches.

"What ship is that?" asked the elder of the two officers, whose gold-lace distinction marks showed that he was a lieutenant-commander.

"Yacht Diomeda," replied Hamerton promptly.

"You are foreigners?"

"Yes, British."

"Said I not so, Heinrich?" said the senior officer to his companion in a tone of triumph. "Ach! Why have you not your ensign hoisted on the mainmast-head? Why, indeed, are you flying no ensign at all? Do you know this is a forbidden anchorage?"

To reply to this battery of questions, rapped out with a harsh guttural voice, was a matter of difficulty to Hamerton, whose acquaintance with the German language was somewhat limited. Accordingly he solved the difficulty by answering the last.

"I did not know this is a forbidden anchorage, Herr Lieutenant. That being so, I will change into more suitable attire, and shift my berth as soon as possible."

"What does he want, Jack?" asked the American, who had just appeared from the cabin.

"We've got to clear out. By Jove, we've tumbled into the anchorage off Heligoland!"

For a glance towards the lofty red sandstone rock, fringed with a belt of dazzling white sand and capped by the