Table of Equivalents

Guns

Metric

British

75-mm

3-inch

88-mm

3.4-inch

105-mm

4.1-inch

150-mm

5.9-inch

21-cm

8.2-inch

28-cm

11-inch

30.5-cm

12-inch

38-cm

15-inch

Torpedoes

Metric

British

45-cm

17.7-inch

45.7-cm

18-inch

50-cm

19.7-inch

53.3-cm

21-inch

Distances

All distances in this book are given in nautical miles giving the old Admiralty mile as the reference for the nautical mile. This is one minute of arc subtended along a great circle. It is some 4 feet or 1.248 meters longer than the current nautical mile.

1 nautical mile = 1,853.2 meters = 6,080 feet

1 knot = 1 nautical mile per hour

Compass

360 degrees in a circle

32 points in a circle

1 point = 11¼ degrees

8 points = 90 degrees

16 points = 180 degrees (reversal of course)