* SHIPS' LIGHTS AND REGULATIONS 199
the beam on each side (that is, over an arc of 20 points), and be visible
at a distance of at least 5 miles.
9. Where must this masthead light be placed?
On, or in front'of, the foremast, or if the vessel has no foremast then
in the fore part of the vessel. It must be at least 20 feet above the
hull, and if the breadth of the vessel exceeds 20 feet, then at a height
not less than such breadth; it need not, however, be placed higher than
40 feet in any case.
10. Does this apply to every steam vessel?
It applies to all steam vessels over 40 tons gross tonnage. Where
the tonnage is less than 40 the masthead light may either be as above,
or if not as above may be placed on or in front of the funnel at least
9 feet above the hull, showing a bright white light over the same arc
visible at least 2 miles.
11. Do steam vessels under way carry an additional masthead light ?
A second one may be carried exactly similar to the first. They
must be placed in a line with the keel, the forward light at least 15 feet
lower than the after one, and the horizontal distance must be greater
than the vertical.
12. What advantage is gained by carrying two masthead lights?
Other vessels can see approximately the direction in which the one
showing two masthead lights is heading. If approaching end on or
nearly end on, the lights would appear vertical or nearly so. If broad-
side on, the horizontal distance would appear greater than the vertical.
Also other vessels would notice if the course was being altered,
13. Describe the side-lights for steamers under way?
A green light on the starboard side, and a red one on the port side.
They must be fitted with inboard screens extending at least 3 feet for-
ward from the light, and must be placed and constructed so as to show
an unbroken light from right ahead to 2 points abaft the beam, and to be
visible at least 2 miles.
14. What lights do sailing ships and vessels being towed carry?
The side-lights as described for steamers, but no masthead light*
15. What other light may vessels show?
A white light at the stern visible 6 points from right aft on each
side of the vessel at a distance of 2 miles.