A floating traffic jam quickly developed as we joined a line of other boats, not unlike a solemn funeral procession, through a narrow channel behind a half-submerged vessel under tow and en route to a nearby boatyard, escorted by an entourage of local harbor patrol and Coast Guard vessels.
Some of us feathered our throttles to keep idle speeds in check and remain well astern of the stricken vessel, the 100-foot hawser serving as the tow line, and the heavily burdened TowBoatUS as its captain skillfully negotiated the circuitous channel.
All of the boaters cooperated in offering the tow boat and its tethered load a wide berth—except, that is, for one impatient boater who ignored common sense and tried to pass on the north side of the channel between a shoal and the taut hawser.
A piercing blast of a siren and a public scolding over the loudspeaker from one of the harbor patrol officers put a halt to this ill-advised shortcut, and the chagrined captain sheepishly backed away and rejoined the procession amid the disapproving scowls of other boaters.
Giving vessels in tow a very wide berth ranks as a key tenet of prudent seamanship. By the way, a vessel in tow also refers to one that is being pushed and hauled along the side (on the hip), as well as one being pulled. Whichever the case, the two vessels are often referred to collectively as a “tug and tow” or simply as a “tow.” In these scenarios, a vessel in tow lacks power, and sometimes steering, and the towing vessel is extremely limited in its ability to maneuver or adjust speed.
A tow is always designated as the stand-on vessel. In any encounter, you are the give-way vessel. That means granting a tow the widest berth possible, giving it room to maneuver, especially when it’s one vessel pulling another, which is arguably the most dangerous to boaters. Navigate well astern of the tow and avoid crossing the bow at close range or, heaven forbid, cutting between a towing vessel and the one behind it. This has happened, and the results are almost always tragic.
During daylight hours, recognizing a tow usually proves easy, although with a hawser stretching 200 meters or more between a tug and tow, inexperienced boaters might not associate one vessel with the other until it’s too late.
That is why a vessel engaged in towing with a line exceeding 200 meters will fly a black diamond day shape. The towed vessel or object will show a black diamond as well. A vessel towing with a line that is less than 200 meters does not need to display a day shape.
Read Next: How to Safely Tow Other Boats
After dark, recognizing one vessel pulling another grows more difficult. In this case, the towing vessel is required to exhibit two masthead lights (three lights if the tow is over 200 meters) in line, as well as a yellow light situated over the stern light. The towed vessel must exhibit side and stern lights. Make sure you remember this when boating at night.
Fog presents the greatest challenge in distinguishing a tow, particularly one vessel pulling another, but a radar with good target separation will help you see the two in relatively close association, a sure tipoff of a tug and tow.
An AIS overlay on the radar or a chart plotter will identify and confirm a tow. Press on the AIS on-screen icon to call up a page that describes the vessels engaged in towing, their size, speed, course, closest point of approach, and more. This will give you information you need to give the tow a wide berth.
