Sound Signals and Restricted Visibility
Last but not least, sound signals! Sound signals are a rudimentary form of communication and have been around since Fred Flintstone squeezed a Pterodactyl strapped to the top of his car. Since then, horns and whistles have evolved and their use for navigational sound signals falls into one of two categories: signals used when in sight of other vessels and signals when not in sight of other vessels. The majority of recreational boaters don’t understand how to apply these signals and in most cases avoid using them. I’ve heard several reasons for the lack of use by recreational boaters, such as they confuse other vessels in the area, or “Other boaters don’t use them, so why should I?” But mostly it’s just not part of the culture. Realistically, if you are paying close attention and have good situational awareness, you shouldn’t have to use sound signals in all but close-quarter situations.
All vessels, motorized or non-motorized, are required to carry a sound-producing device or as defined in the rules, a “whistle.” In Rule 33, the word whistle means “any sound signaling appliance capable of producing the prescribed blasts and which complies with specifications in Annex III to these Rules (33 CFR part 86).” So a horn or whistle, manual or mechanical, that can produce an audible sound, is required. For vessels under 12 meters, 39.4 feet, there is no specific audible range listed. Vessels over 12 meters but less than 20 meters (65.6 ft) must have a half-mile audible range. Realistically you might only hear a sound signal from another small vessel when within 100 yards so this is why you should closely adhere to Rules 5, 6, 7 and 8, by establishing a risk of collision in plenty of time where simply maneuvering early will remove the risk. Again, if you mitigate the risk early enough, sound signals may not be necessary. Regardless, recreational boaters should know the basic signals and make every attempt to use them when the situation warrants.
I made a promise in my first article that I was going to stay away from international rules because they are so similar to inland rules that the differences would just be confusing, but sound signals are not one of those instances. First, we need to discuss where the boundaries are between international and inland rules. The boundary lines are charted and also listed in the Code of Federal Regulations. They are also listed in the back of the navigation rules book. These boundary lines are called lines of demarcation, normally a line one can infer between jetty tips or headlands on smaller estuaries where coastal waters transition to inland waters. Larger bays and sounds will normally remain under international rules, so it is always best to check which rules apply in the waterway you intend to use. The difference between the two is that under international rules your maneuvering signals are signals of action whereas under inland rules maneuvering signals are signals of intent. For inland rules, if risk of collision exists and you sound one short blast of the horn, you are intending to bring the other vessel down your port side, turning to starboard. The other vessel would repeat that signal to indicate that it understands and the maneuver is made. International rules are signals of action. If you’re in international waters and risk of collision exists or if you’re in a waterway or channel and turning into the direction or possible path of other vessels at a bend or channel entrance, the maneuvering signals are sounded and the maneuver completed. There is no requirement for the other vessel to respond.
For recreational vessels in inland waters, the signals are pretty basic and easy to remember because there are only two: a short blast and a prolonged blast. The term short blast means a blast of about 1 second’s duration. The term prolonged blast means a blast from 4 to 6 seconds in duration. These can be in different combinations, but if you separate those signals that are used when in sight of another vessel and those when not in sight, it becomes very easy. Let’s talk about when vessel are in sight of each other; Rule 34. No matter the situation, always think, “If I sound one short blast, it means I intend to turn to starboard and bring the other vessel down your port side.” Similarly, two short blasts turning to port and bring the other vessel down your starboard side. That’s it! You have just graduated the “signals when vessels are in sight of one another,” course.
As with any of the rules, there is a fail-safe clause known as the “Danger Signal.” When doubt exists as to the intentions of the other vessel, you should sound 5 or more short blasts in rapid succession: (d) When vessels in sight of one another are approaching each other; and, from any cause, either vessel fails to understand the intentions or actions of the other, or is in doubt whether sufficient action is being taken by the other to avoid collision, the vessel in doubt shall immediately indicate such doubt by giving at least five short and rapid blasts on the whistle. So if you are in a situation where the risk of collision exists and you are unsure, or the other vessel operator is unsure, of what’s taking place anyone can sound 5 short blasts of the horn. When you hear that signal, it means that you should take immediate action, under the applicable rule for that situation, and maneuver accordingly. Assuming that the signal does not apply to you could be a deadly assumption.
If you can make contact with the other vessel on the VHF radio and agree on how to pass each other, then whistle signals are not required. (h) A vessel that reaches agreement with another vessel in a head-on, crossing, or overtaking situation, as for example, by using the radiotelephone as prescribed by the Vessel Bridge-to-Bridge Radiotelephone Act (85 Stat. 164; 33 U.S.C. 1201 et seq.), is not obliged to sound the whistle signals prescribed by this Rule, but may do so. If agreement is not reached, then whistle signals shall be exchanged in a timely manner and shall prevail.
Operating in restricted visibility has the highest factor of risk that you will encounter while recreational boating. Great care and alertness should be a priority and unless there is some greater compelling reason to be underway, it’s probably best to remain at the dock until conditions improve. The worst-case scenario as far as restricted visibility goes, would be fog. But in the case you are caught up in the fog, your awareness should be heightened. Before we get into Rule 35, we need to go back to establish the conduct of vessels operating in restricted visibility before addressing the signals required.
In Rule 19, vessels have a specific responsibility when navigating in or near an area of restricted visibility. In a nutshell, it is a rule of detection and avoidance where the rules for a vessel in sight of one another don’t apply. Rule 19 is about reducing risk. We know the audible range of a sound signal is approximately one-half mile. So you can surmise that if your visibility is less or close to a half-mile then it is an appropriate time to take this rule into account. What do you do? First, slow down; (b) Every vessel shall proceed at a safe speed adapted to the prevailing circumstances and conditions of restricted visibility. A power-driven vessel shall have her engines ready for immediate maneuver. You have to fall back to the basic rules for vessels operating in all conditions of visibility. That would be Rules 5 through 8. Maintain a proper lookout and use passengers to help you observe, through sight and sound, what is happening around you. Make sure that lookouts (your passengers) are properly briefed and that their attention is solely focused on detecting the presence of other vessels in the area. Never assign lookouts to other tasks. Their focus should only be toward detecting other vessels so you can determine if a risk of collision exists. You should also operate at a safe speed for the prevailing conditions so that you can take proper and effective action to avoid a collision if necessary. Never operate at a speed where you are unable to stop within a distance appropriate to the prevailing conditions. A good rule of thumb is to be able to stop within your boat’s length. Use all available means to determine if the risk of collision exists. Most importantly, if the circumstances of the case admit, you shall take positive action in ample time with the due regard to good seamanship to avoid a collision. So navigation lights on, slow down, post lookouts determine if a risk of collision exists, even if you can’t see the other vessel, and take action to avoid a collision.
So how do you avoid a collision if you can’t see the other vessel? (e) Except where it has been determined that a risk of collision does not exist, every vessel which hears apparently forward of her beam the fog signal of another vessel, or which cannot avoid a close-quarters situation with another vessel forward of her beam, shall reduce her speed to the minimum at which she can be kept on course. She shall if necessary take all her way off and, in any event, navigate with extreme caution until danger of collision is over.
So let’s say you have radar. (d) A vessel which detects by radar alone the presence of another vessel shall determine if a close-quarters situation is developing and/or risk of collision exists. If so, she shall take avoiding action in ample time, provided that when such action consists of an alteration of course, so far as possible the following shall be avoided:
(i) An alteration of course to port for a vessel forward of the beam, other than for a vessel being overtaken;
(ii) An alteration of course toward a vessel abeam or abaft the beam.
So in order to make this happen, we need to go back to the sound signals used when vessels are not in sight. Rule 35 As a power-driven vessel underway, you only need to concern yourself with two signals. Underway and making progress (make way), would be one prolonged blast (4 to 6 seconds in duration) of the whistle every two minutes. If you are stopped and drifting or not making way, you sound 2 prolonged blasts every 2 minutes with a one-second interval between blasts. That’s it! If everyone is following these rules, you should be able to tell what direction another vessel is from you and how close they are. If the sound is coming from a constant direction and is getting louder you are likely at risk of collision. Slow down or stop.
If you hear any other signals such as one prolonged and two short or one prolonged and three short, all you need to realize is you need to stay clear of that vessel and follow Rule 19 above. Vessels sounding those signals are higher in the hierarchy (Rule 18) and you would be required to avoid them even in good visibility. For those with radar, if you detect any vessel ahead or forward of your beam turn to starboard. If the other vessel is abeam or aft of you, do not turn toward it and continue to monitor your radar and adjust as things change. In any situation, good or bad visibility, if you are uncomfortable or unsure of the situation STOP. Monitor the movement of the other vessel and take the best course of action necessary to avoid a collision.
Hopefully, you can see that there is nothing mystical about sound signals. My persistent message throughout all of these articles is if you can identify the risk of collision early, make a reasonable course adjustment to remove the risk of collision, you will probably never use sound signals. When you determine that risk of collision exists, letting people know your intentions, or in the case of restricted visibility, notifying them of your presence with sound signals is merely being a safe and responsible boater. Staying focused on the safety of everyone on the water should be your primary concern. This is also the reason why we have and should follow all the rules of navigation. The rules benefit all boaters and waterway users. It’s never wrong to ask someone to help interpret the rules if you don’t understand them. To disregard them can be a costly or fatal mistake.
As a final thought, no matter the situation, the vessel Captain has the ultimate responsibility for safe navigation. Whether it is a kayak or a superyacht, the responsibility and liability falls on their shoulders. Having a working understanding of the navigation rules is the single most important skill a boat operator can learn. Always remember, “Superior Mariners use their Superior Knowledge to avoid situations that require their Superior Skills.”