They may be laying pipeline, building an underwater structure, or doing commercial salvage diving. So how do you know which side to pass them on? Read on to avoid damage to your hull, keel, rudder, or propeller and shaft now!
How to Find the Clear Path by Day
Look to the Navigation Rules to tell you what those vessels engaged in underwater construction need to show by day or night. In earlier articles, we discussed dayshapes–which are geometric shapes hoisted by day to signal to others your status or the nature of your work.
Navigation Rule 27 requires any vessel restricted in her ability to maneuver–which means she will be unable to get out of another vessels way because of her work–to show a black ball over a black diamond over a black ball by day. This must be hoisted high in the rigging so that it can be seen from any location.
In addition, those vessels doing underwater construction must show dayshapes to indicate the dangerous side and dayshapes to indicate the “clear to pass” side.
Remember this memory key “balls are bad; diamonds are delightful.” Vessels engaged in underwater construction show two black balls on the danger side (Bad) and two black diamonds on the clear side (delightful).
Break dayshapes into separate vertical signals. The middle signal here shows a ball-diamond-ball. That means one thing: restricted in ability to maneuver. When this shape has been hoisted along with two black balls, these indicate the danger side. Diamonds indicate the “safe to pass” side.
How to Find the Clear Path by Night
Use extra caution when sailing or powering at night. Learn to recognize the lights that indicate a vessel restricted in its ability to maneuver. They are one red all-around-light, over one white all-around-light, over one red all-around-light; all shown in a vertical line. Red over white over red. If you sail or cruise you may see this display.
Remember that this signal by itself always indicates that this vessel will be unable to maneuver without extreme difficulty. If you are under sail or power, stay clear to avoid damage or risk of collision.
Realize that dredging vessels at night will be flooded with deck and superstructure lights. It may be tough to pick out those lights that indicate the safe side for passage. Stand off; use a binocular; communicate with the dredge captain. Verify first before you commit!
Stop or heave to if necessary once you sight a vessel that shows red-white-red. I cannot emphasize this single point enough. Understand the rest of the story before you proceed. Look for additional lights that tell you more about them. Realize that some tug boats show this configuration, as do vessels servicing aids to navigation, launching or recovering aircraft, or diving. And so do those engaged in underwater dredging or pipe laying.
Those engaged in underwater dredging or operations–in addition to the lights described for a vessel restricted in her ability to maneuver–must show:
Two red all around lights in a vertical line to indicate the danger side.
Two green all around lights in a vertical line to indicate the clear side.
One of our instructors at the Chapman School came across a construction barge in the St. Lucie river near the inlet late one afternoon. The barge appeared to have hoisted the proper dayshapes: ball-diamond-ball along with the additional two balls and two diamonds. But–something just didn’t look right!
So, my friend brought the boat to a stop, broke out the binocular and scanned left and right. Funny thing was, the barge was dredging on the side with the diamonds hoisted. My friend called the barge skipper on the radio to ask what was going on.
And sure enough, the barge skipper had forgotten to shift dayshapes when they turned the barge around. Just another example of the old “trust but verify” mantra. When in doubt stop or heave to.
Communicate with the other vessel. If necessary, find another route or at nighttime, wait until daylight if in doubt. It could save you a hole in the hull, a cracked keel or rudder, or damaged propeller or shaft.
Learn to sail like a pro when you recognize the most important navigation lights used by special vessels to indicate danger or safety. Gain the confidence you need to sail day or night on the waters of the world–and keep your sailing crew safe and sound–wherever in the world you choose to cruise!
Courtesy of Captain John at www.skippertips.com