Start by being conscientious on
watch. That may seem obvious, but inadequate watch keeping
is a major cause of collisions at sea.
in the cockpit every 5 minutes and slowly scan of the horizon,
360º. It’s a simple yet vital routine.
When you spot a ship underway,
first determine which side you're seeing. In
daylight it’s usually obvious. At night, however, you have to
read the navigation lights and these can sometimes be confusing.
Ships use a variety of lighting configurations to indicate
special circumstances like restricted in ability to maneuver,
fishing or towing. (Note:
It’s especially important to
recognize tow vessels. Tows can extend as much as 1500 feet in
open ocean, occasionally trailing two 300-foot barges in tandem.
Always give offshore towboats at least a half-mile when passing
memorized all the navigation light configurations and their day
shape counterparts, you’ll need a way look them up quickly when
they appear. Keep a copy of Navigation Rules for International
and Inland Waters on board. It contains illustrations and
details of lights, shapes, sound signals and other aids and
rules for avoiding collisions at sea. A plastic-coated
quick-reference card is also handy for the cockpit.
In most cases, though, the nav
lights on a ship are straightforward: port, starboard and stern
(red, green and white) running lights PLUS a pair of white bow
lights in alignment fore and aft, the after light positioned
higher than the one forward. Also called “masthead lights” or
“steaming lights,” bow lights are visible from ahead in a
225-degree arc. They tell you which way the ship is headed,
i.e., from the higher light aft towards the lower one forward,
and therefore which side of the ship you’re seeing. One directly
over the other means the ship is head on. You’ll often make out
the white bow lights before seeing a ship’s red or green
OK, you’ve determined which side
of the ship you’re seeing. If her port side is facing your
vessel’s port side (or her starboard is to your starboard), then
there is no present risk of collision. Maintain your course and
keep an eye on the ship to be sure she does the same.
If, on the other hand, her port
side faces your starboard or vice versa, then it’s possible your
courses are converging. In that case, immediately begin taking a
series of compass bearings on the ship. A handheld compass with
a nightlight is handy for this, but a binnacle-mounted cockpit
compass works, too. Sit with the compass between you and the
ship, scrunch down so you’re looking across the top of it, and
line up the instrument’s center pin with the distant vessel.
Then raise your head a little so you can read the mark with
which the center pin is aligned on the compass card’s far
perimeter. This is the ship’s compass bearing in degrees. Make a
note of it. Then take another reading in a few minutes, and
another a few minutes after that until you’ve established a
trend. If the ship’s bearing is changing she will pass safely.
If her bearing remains the same then your paths are converging;
you’re on a collision course.
You can also use a radar’s EBL
(electronic bearing line) to track a ship’s bearing, but your
boat’s heading must remain perfectly constant. In lumpy sea
conditions you’ll get more useful readings from a compass.
Still, radar can track the target’s range, letting you estimate
how much time you’ve got before the vessels are in extremis.
Suppose a ship changes bearing
from 90º to 100º over a period of several minutes. She’s moving
from left to right across your field of vision. If she’s off
your vessel’s port side she’ll pass across your bow. If she’s
off your starboard side she’ll pass astern. This change in
bearing could also conceivably indicate that the ship is moving
parallel to your course but at a different speed. However, since
you just sighted her where she wasn’t visible 5 minutes earlier,
either the visibility just got a whole lot better or (nearly
always) the ship has been moving closer and will continue to do
so until she has passed.
If the ship’s bearing does not
change over a 5 to 10 minute time period, then assume you’re on
a collision course. It is possible she’s running parallel to
your course at the same speed – that would also result in a
constant bearing - but again if she just recently hove into view
she’s more than likely moving towards you. If nothing changes
the two vessels will soon arrive at the same place at the same
If You’re On a
Once you’ve concluded you’re on
a collision course with a ship, decide who has right of way.
It’s each captain’s responsibility to know the applicable rules
and act appropriately. Again,
for International and Inland Waters is your best information
under sail doesn’t necessarily give you right of way. In
addition to the more commonly known Steering and Sailing Rules
governing vessels on converging courses,
Rule 18, Responsibilities Between Vessels states in part: “…
sailing vessel underway shall keep out of the way of: a vessel
not under command; a vessel restricted in her ability to
maneuver; a vessel engaged in fishing.” An earlier part of the
book defines these terms; a later section describes the day
shapes and nightlights these vessels exhibit so you can identify
them. Of course, when your engine is running – even if your
sails are up – then a ship approaching from your starboard side
has the right of way.
If you determine
that you’re on a collision course with a ship and that she has
the right of way, alter your vessel’s course abruptly and
substantially to pass behind her. Continue observing and taking
bearings until it is clear you’re passing at a safe distance.
Resume your original heading after you see the ship’s transom or
If, however, you
have the right of way, then your responsibility is to maintain
your course and speed… up to a point.
question now is whether the ship’s crew sees you, whether they
even know you’re there. Don’t take it for granted. In an
alarming number of cases they do not, and here is where yachts
sometimes get into trouble.
There are many reasons why a
ship’s watch officer might not see a yacht: He could be busy
attending to all manner of ship’s business, or simply absorbed
in a good book or some similar distraction. He might even have
dozed off. Not all commercial vessels maintain a proper watch at
all times. This is why you must.
Even if they are watching they
might not see you. Ships carrying stacks of containers forward
of the bridge often have a substantial blind zone ahead, and
even with a clear view the night watch in a ship’s wheelhouse
may not see your running lights.
lights are more visible than lights mounted on the pulpit, which
can be obscured by waves, but it’s still difficult to pick out a
lone red or green running light in sufficient time for a ship to
do anything about it. Against a background of shore lights or in
weather it’s even more difficult.
Neither should you assume your
boat is visible on their radar screen. A seagoing yacht should
carry a radar reflector aloft - this helps a lot – but some
ships turn their radars off at sea to reduce maintenance.
Considering all that, perhaps we
should be grateful they ever see us at all. When they do and the
ship’s watch officer determines that you have the right of way,
he will alter course to avoid you, usually (but not always)
passing behind your vessel. You might perceive a change in the
ship’s angle, though it may be slight. Then you’ll note changes
in her bearing, confirming that she will now pass safely.
If She Keeps Coming
When you have the right of way
and the ship does not alter course early and obviously, you
should assume they haven’t seen you. Call them on VHF radio
channel 16 while they’re still a few miles away. All ships are
required to monitor VHF 16; that’s the only correct radio
frequency for hailing a nearby ship.
If you’ve managed to read the
ship’s name through binoculars, hail her by her name. Otherwise,
initiate VHF radio contact by saying something like, “Calling
the ship heading (their approximate heading, such as
‘southeast’) near latitude (your position) and longitude (your
position).” Repeat this a second time and then add, “This is the
sailing vessel (your boat’s name). Over.” Repeat the call
several times at 15- to 30-second intervals.
If they respond, say something
like, “Good evening. This is the sailing vessel, (your boat’s
name), about 3 miles off your (port/starboard) bow. We appear to
be on a collision course. I believe I have the right of way. Do
you see my vessel ahead of you? Do you intend to alter course?
There may be a delay while they
scramble to find you through binoculars. Then (hopefully)
they’ll say something like, “Roger, captain, we see you and
we’re altering course to pass astern of you.” At least, that’s
how it goes sometimes.
Unfortunately, when sailors call
ships on VHF 16 in these situations, more than half don’t
answer. More than half! Maybe the watch officer doesn’t
understand English. Maybe he’s just not listening.
Become More Visible
If you can’t raise the ship on
the VHF and they still haven’t changed course, at night switch
on your spreader or deck lights, bathing the foredeck and sails
in thousand-candlepower brilliance, hoping to startle the ship’s
watch from their torpor. You could also flash a spotlight at
their wheelhouse, but only momentarily so it won’t interfere
with their ability to read your navigation lights. Then redirect
the light onto your sails.
White “attention” flares –
handheld, meteor or parachute - are excellent for this
application. Keep them close to your steering station, ready for
immediate use. With meteor flares fire at least two, 10- to
15-seconds apart; the first to catch their eye, the second to
help them pinpoint your position. Do not use any other color
flare! Use only white flares for collision avoidance.
Do everything you can to alert
an approaching ship to your presence early, while they’re still
at least a couple of miles away. The watch officer needs time to
assess your range, bearing, heading and right of way, and to
alter course. Ships cannot change direction quickly.
If They Still Don’t
You’ve done all you can, yet
here comes this deaf, dumb and blind gargantuan bearing down
with no sign of turning to avoid the impending collision. You
clearly have the right of way, but as the old sailor’s adage
goes, you could be dead right. Now what?
There comes a point when you
simply have to get out of their way. With some fast, timely
maneuvering aboard a sailboat, sometimes involving a 180-degree
about face and a prodigious burst of auxiliary engine power, you
can avoid an oncoming ship. Announce your intention on VHF 16.
Then change course abruptly and substantially so that it’s
obvious to an observer.
Above all don’t wait too long to
do it. One mile is about as close as you should ever let an
unresponsive ship get on a converging course before taking
evasive action. Farther is better. Remember, if she’s
approaching at 20 knots, one mile is a mere 3-minute window of
opportunity. Once you’ve changed course, immediately take more
bearings to be sure your nemesis didn’t simultaneously change
hers and so put you onto a new collision course.
The AIS Advantage
Today there is new hope for
besieged boaters. The marine automatic identification system, or
AIS, takes much of the guesswork out of collision avoidance,
providing real time data on commercial carriers within its +/-
25-mile range. It can plot potential collision courses on a
display screen, tell you the ship’s owner, classification,
speed, heading, and of particular interest in close encounter
situations, her name.
Your VHF transmission will reach
every radio in a 25-mile radius. It’s extremely helpful to
identify the specific vessel that’s about to run you down and
call her by name on channel 16. This clarifies which ship you’re
trying to warn off, encourages a non-English speaking watchman
to fetch someone who understands what you’re saying, and
virtually forces them to answer your call because they know that
you know who they are. If they don’t respond and then endanger
your vessel, you can later file a complaint with the ship’s
owner. No captain wants that sort of black mark on his record.
In most cases he will reply if you call his ship by name on VHF
16. You can then advise him that your vessels are on a collision
course, that you have the right of way, and that you would
appreciate it if he’d alter his course to avoid you. Invariably
he will comply.
Class B recreational vessel
‘send & receive’ AIS transponders cost $500 to $1,000, a modest
investment for such a potentially valuable tool. However, in
deference to the KISS principle the prudent mariner will still
take multiple compass bearings early on to determine whether his
vessel is on a converging course with a ship. And while a ‘send
& receive’ transponder will also put your vessel on the ship’s
AIS display screen, be prepared to get out of their way - just
in case the ship’s watch officer isn’t watching.
1) Scan the horizon
every 5 minutes.
2) Determine whether a
sighted ship is: