| |
you, steaming a few knots faster than you are, it is safe
to estimate that the other ship's speed is about 12 to
15 knots.
A readily visible aid in estimating speed is a ship's
bow wave and stern wake. A bow wave is the wave
of water the bow of a ship makes as it travels through
the water. As a ship travels faster, the bow wave
becomes larger (figure 13). A stern wake is the
phosphorus trail that a ship leaves as it travels through
the water. Unlike the bow wave, it is a calm, white-
colored water. As a ship travels fast, the stern wake
increases in length; when the ship slows down, the stern
wake decreases.
The bridge and CIC do not expect accurate, to-the-
exact-knot speed reports from you. However, a good
estimate is always valuable and can be used as a
Figure 13.—Bow wave and stern wake.
27
|
