(e) Masters were cautioned to hug the coast, as far as navigational facilities admitted, when making coastal passages.

[Transcriber's note: Chart A is a navigational map of the waters southwest of England, with approach routes marked.

[Transcriber's note: Chart B is a navigational map of the waters southwest of Ireland, with approach routes marked.

Mining operations had necessarily to be carried out at night, and as there were no navigational aids in the way of lights, etc., in the Heligoland Bight, the position in which our mines were laid was never known with absolute accuracy.

It is appropriate to close this chapter by giving a synopsis of the losses amongst our patrol escort and minesweeping vessels between the commencement of the war and the end of 1917 due (1) to enemy action, and (2) to the increased navigational dangers incidental to service afloat under war conditions.

Under the first headingenemy actionthe losses were 8 yachts, 6 motor launches, 3 motor boats, 150 trawlers, 59 drifters, and 10 paddle minesweepers; and the losses due to navigational risks were 5 yachts, 55 trawlers, 7 motor launches, 3 motor boats, 30 drifters, and 1 paddle minesweeper, whilst the total loss of life was 197 officers and 1,782 men.

It appears that "Cherry" thereupon commenced aserious and arduous course of study of abstruse navigational problems which he found exceedingly tough and now despaired mastering.

The site on O344 was one of dozens of such places marked on the navigational maps.

He walked quietly over to his console, sat for a moment without moving, then began to move dials and enter numbers into the navigational program.