142 seamanship secretssame masthead lighting as when a tug is towing a vessel less than 200 meters
astern. See “Solve the Mystery of Two White Vertical Lights” below.)
Stern lighting. The stern configuration depends on the body of water.
Tugs in inland water (see sidebar) replace the stern light with two vertical
yellow lights. Tugs in international waters show a single white stern light.Barges or Vessels Being Towed Alongside or Pushed Ahead
Towed alongside. Sidelights and stern
light. A vessel not under its own power
never carries a masthead light.
Pushed ahead. Drop the stern light
to keep from blinding the tugboat cap-
tain. Add a yellow light between the
bow sidelights. Th e yellow light fl ashes
at least once every second. A vessel not
under its own power never carries a
masthead light.SOLVE THE MYSTERY OF
TWO WHITE VERTICAL
LIGHTS
Th ree white lights in a vertical line mean
one thing: towing astern on a long haw-
ser. But two white lights in a vertical
line could mean pushing ahead, towing
alongside, or towing astern on a short
hawser. Use three easy steps to solve the riddle.- Slow to bare steerageway or stop. Grab your binoculars.
- Study the tug’s masthead. If you see two vertical white lights, look for a
tow alongside or ahead. An additional pair of sidelights or sidelights and
a yellow fl ashing light solve the mystery. - If you don’t see the tow, assume it’s astern. Scan the area behind the tug.
Find that tow before you go!
Quick Guide for Sailboat-to-Sailboat Situations
Why are sailors subject to so many extra rules above and beyond those of power
vessels? Many of these rules are carryovers from the days of square-riggers.
Th ese vessels needed lots of room to maneuver, and unlike many of today’s
sailboats, they had a diffi cult time sailing close-hauled. Th ey also needed moreInland or International
Waters?
Imaginary lines, called lines of
demarcation, mark the boundary
between inland and international
waters. Look near the back of the
Navigation Rules for the exact
boundaries. On coastal charts the
demarcation lines are printed as dashed
magenta lines and labeled “COLREGS
demarcation line” (COLREGS stands
for Collision Regulations). Only the
United States has its own set of inland
rules, and thus, lines of demarcation.
Parts of the U.S.—all of Alaska and
parts of Hawaii and other Pacific
possessions—follow international rules
even on inland waters.