146 seamanship secrets
LOW-VISIBILITY SIGNALS
In low visibility, sound a prolonged blast (4 to 6 seconds) at intervals of
2 minutes. Th is lengthened signal makes sense, for you want to make sure
another vessel knows where you are. Vessels never exchange maneuvering
signals in these conditions because they are not in sight of one another. Th ese
are the three basic low-visibility signals:
One prolonged blast: underway under power; making way through the water
Two prolonged blasts: drift ing under power; not making way through the
water
One prolonged blast and two short (1-second) blasts: sailing or in a special status
(such as tugboats, commercial fi shing vessels, vessels dredging, and others)
See Rule 35 for more coverage of low-visibility signals.
HOW TO ATTRACT ATTENTION TO AVOID DANGER
Th e rules allow you to use the whistle and light to get the attention of another
vessel. You may need to do this to warn another vessel of danger or to avoid a
collision. Be sure not to confuse the other boat by using a specifi c maneuvering
or low-visibility signal.
How to Use the Th ree Factors of the Lookout
Every vessel shall at all times maintain a proper lookout by sight and
hearing as well as by all available means...
—Navigation Rules for International and Inland Waters, Rule 5Look over the quote from Rule 5 again. What do you notice about the priorities
of the lookout? The three ingredients of a proper lookout are as follows:
- sight (visual)
- hearing (sound)
- all available means (including radar if installed)
Each discussion of collision avoidance strategies in this chapter starts with
visual assessment. You must track a vessel by sight until any threat of collision
disappears.
When visibility drops, change your priorities to hearing. Send a crewmember
forward, away from engine or wake noises. Keep noise to a minimum. On large
vessels, use cordless headsets to communicate from the bow to the bridge.
Vessels equipped with radar must use it underway in all conditions, along
with sight and hearing, to assess the possibilities of a collision. Admiralty