Boating Signals

by Captain Ira M. Barocas, NAUI #10126

While hand signals are fundamental to safe diving, nonverbal communication between vessels is prescribed by law. These signals, be they lights, shapes, sounds, or, in the case of diving activities particularly, flags, give information about the size, function, and movement (or lack of it) of a vessel. Diving leaders need to be familiar with the signals necessary to the conduct of safe operations offshore under all circumstances.

Most diving leaders are aware of the common "diver down" signals: the red flag with a diagonal white stripe, and the International Code Flag Alpha pennant; but the customary usage of one should not be confused with the mandatory usage of the other.

The red with white stripe flag is only "unofficial" in the sense that it is not prescribed in any Coast Guard rule or internationally enforced law. It may well be required by a state, county or city statute in whose jurisdiction you are operating, however (some 35 states have legislation concerning this flag). The red and white flag traditionally indicates that there are divers operating in the vicinity. Given this assumption, its deployment on a float is important if the support vessels is drifting or is substantially off site, as in a deep water anchorage. In the usual northeastern scenario, where wrecks are recreationally dived and fished simultaneously, a floating warning can help to keep the props and hooks of passers-by off your head.

Some local statutes require that divers stay within a prescribed distance of the red flag, and that vessels give the flag a considerably wider margin of respect to protect the individuals in the water.

Unlike the red and white flag, which is really oriented towards the diver, the one meter high, rigid replica of the Alpha pennant is a required navigational signal under the International-Inland rules of Navigation, and must be shown on vessels engaged in a diving operation that restricts their ability to maneuver. The last phrase is the key.

The flat replica gives other vessels notice that the dive boat is under a special circumstance that makes it incumbent on other vessels underway to avoid collision. Strictly speaking, it doesn't do anything to protect free-swimming sport divers. It is (hopefully) the common sense of other boaters that will keep a good margin around the vessel.

Clearly, the use of both signals whenever there are divers in the water is most practiced. I believe NAUI diving leaders should take the lead in making this proposal a sport diving standard, educating their students and their local boating community.

In addition to these flags, Nav rules require that certain shapes be displayed under circumstances applicable for night operations. For instance, a vessel at anchor during daylight must show a properly sized black "ball"shape. It should also show three vertical shapes--a ball, diamond, ball indicating underwater operations hampering her ability to maneuver(Navigation Rules, Rule 27, Sect. d).

Although, technically, the described shapes are required if involved in "dredging or underwater operations," and are generally more applicable to commercial situations, the fact is that a dive vessel should, whenever possible, notify passing traffic that it is not going anywhere and why. Keeping a good surface lookout for traffic is part of the job, and may mean using the radio to help divert traffic as well.

During a major 28 day offshore salvage operation with every imaginable signal in place, prior published warnings in the Local Notices to Mariners, regular VHF hazard messages, large buoys on the four anchors, on a vessel with over eight stories of superstructure, the only way we could get some vessels to respect our working boundaries was to broadcast a demolition warning! Their subsequent turns made interesting radar plots, but I don't think the risk there was as great as sport diving around small boats close to shore, especially at night.

From one-half hour before sunset to one-half hour after dawn, the anchor ball is replaced by an all around white light. Dive boats may also use all their deck and work lights to augment the anchor light, but reserve a couple of spots to illuminate the well known fags as well. The three shapes are replaced by three all around light; red over white over red.

This is a "belt and suspenders" approach, but well justified despite rule 27 sect. E of the Navigation rules which gives boat operators a loophole, allowing them to judge if the size of the vessel makes showing the prescribed lights and shapes impracticable. Try to imagine the nightmare of defining "impracticable" in court after some unfortunate incident. That loophole turns quickly into a noose, and the consequences of an unfavorable ruling could be disastrous.

Without written approval or exemption from the published requirements from the coast Guard or other governing body, the vessel and operator could be deemed in violation of the rules in the event of an accident with another vessel. This could enormously increase your liability. Given the prevalent approach in lawsuits, it's important to armor ourselves in scrupulous procedure. I've not heard of any insurance glitches as a result of these full compliance issues...yet. I also doubt any same person would volunteer for a test case. I believe that NAUI leaders should encourage the use of these prescribed shapes and lights in the dive boats they use.

Lights, shapes, and flags are all fine when one can see, but there are also prescribed sound signals for conditions of restricted surface visibility. Divers should know the difference between a fog horn and possible recall signals to avoid confusion and accidens. Nor should these signals interfere with each other causing confusion for mariners near your dive area.

Since sound propagation characteristics in limited visibility at sea are erratic, and underwater sound signals generally ubiquitous and somewhat difficult to distinguish, easily differentiated tones must be employed. A vessel anchored in restricted visibility is required to sound its bell (Oh!! That's what the bell is for!!?) rapidly for five seconds every minute (Article 15, Sec d) unless in a special anchorage. The bell might also help buddy teams find their way back to the boat if the weather turns foggy.

The whole thing probably starts to seem excessively complicated and maybe a little fussy, but the rules are in place and enforced, insure that all water users can operate safely in all circumstances. The Navigation Rules enable us to inform other vessels of the status and maneuvering abilities of our vessels while diving, and grant us the consideration we require from other surface vessel traffic.

Diving leaders can best protect themselves and their students by using for their activities only reputable professional dive boats with licensed personnel. These individuals will most likely be aware of the applicable rules and practices under which they operate. Leaders who operate their own vessels for certification and classes should b e licensed, and thoroughly familiar with correct signaling procedure.

Questions about what is or is not required are best addressed to the ruling authority in your area, such as the Coast Guard or the equivalent state agency for inland boating and diving. Copies of the Navigation Rules are available from the Department of Transportation, and are generally at any nautical bookstore, chart distributor, or marine chandlery.

Insofar as the flags and signals are concerned: use them all appropriately at all times while diving, and encourage other to do so as well. Maintaining standards is what NAUI leaders are all about.

Sources - May/June 1990 copyright NAUI. All rights reserved.

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