. . .Eight sectors were thus provided for patrol, and all kinds of combinations could be worked out.[Pg 34] As the circumferential lines were ten miles apart, each section of a sector was searched twice on any patrol when there was good visibility.

A chart was kept showing the positions, dates, and times of day that submarines were fixed by wireless, and it was from this chart that the sectors which would pay for searching were determined.

The pilots were to boom out from Felixstowe to the North Hinder, a distance of fifty-two sea-miles, fly out a radial arm as instructed, and then proceed along the patrol lines in the sectors to be searched, sweeping from the outside to the centre, returning to the North Hinder and so to the base.

Navigation over the sea, where one square mile of water looks exactly like every other square mile, is more difficult than finding the way over land. The only fixed objects by which a pilot can check his calculated . . . Read More