#COLREGs – Rules -7-8-9
This column is about techniques of avoiding collisions with an emphasis on narrow channels.
Rule 7 – Determining the Risk of Collision
Have you ever walked across an office lobby or a plaza and, out of the corner of your eye, you see someone who you can “just tell” is going to collide with you unless either you or they speed up or slow down? How can you “just tell”? Well, you weren’t just born yesterday – you could tell because everything in the background and around you was changing except the angle between you and the other person! Child’s play! So why do boats collide?
In “close quarters”, it is easy to see that the angle between you and another person is a constant. On the open water, it may be a considerable distance to other points of reference such a point of land behind the other boat. When distances are great, measuring the angles in your mind’s eye is just too unreliable to be of any value. But you don’t need to use a distant object! Use your boat! Sight the other vessel over an object on your boat – a stanchion of the bow rail is pretty handy. If the other boat keeps a constant relationship – a “constant bearing” in maritime lingo – collision is absolutely certain! Rule 7 specifically says that you must use “all available means” to make that determination. If you have radar, use it. But a simple bow-rail stanchion will be as reliable as any computer or radar on the market – constant bearing means collision!
Rule 8 – Action to Avoid Collision
How many times in your life have you walked up to someone who was walking exactly in the opposite direction and you both did the “stutter step” – you turn to your right just as they turn to their left so you both stop – and then you both reverse course simultaneously, again… and again… and again? Finally, you both stop “stutter stepping” and wave the other past…
We’ve written earlier about the “stand-on” (hold course and speed) and “give-way” (take early and substantial action to keep clear) vessels. #COLREGs-Rules13 (Overtaking), #COLREGs-Rule14 (Head-On) and #COLREGs-Rule15 (Crossing) are all about these obligations. So, what is Rule 8 about? You’re stand-on and collision is still possible – now what??
The give-way vessel must take early and substantial action to keep clear. Given that, changing course is easier to “telegraph” as a move versus just slowing down. Unless you come to a dead-stop (bow wave flattens, the bow itself dips down/forward and the boat settles on her waterline), the stand-on skipper may not be sure of your intentions. But, imagining that you are the stand-on vessel and the give-way is not telegraphing a proper action to avoid a collision, you must assume one is imminent and, having applied Rule 7 in your mind’s eye, you start to take your independent action.
1. You never hesitate to use your horn in the car. Why do you hesitate in your boat? You may give 5 or more short blasts that might just get that skipper to port (you are on his right) to wake up and at least throttle back.
2. You may take any action yourself re the boating’s heading – except turning towards port when the offending vessel is on your port side (see “stutter step” above!)
3. If collision seems imminent unless you do something, you must do something. Blast away on the horn and “take the most effective action” to avoid the collision now upon you. Dead stop may be best. Turning so as to be going in the same direction, but hopefully only parallel, as the offending boat may be best. Use judgment. Try dead-stop as a first try since the combined velocity is lessened if both of us aren’t going 20 knots at crunch time.
Rule 9 – In a Narrow Channel
Is there any other when under stress?
A channel is defined as “narrow” when boats in it are severely limited in room to maneuver – which is also related to the relative sizes of the vessels themselves, with the smaller vessel subject not just to the "watery aspects" but also to the physical aspects related to the other, larger vessel.
So, stay as far to the starboard side of the channel as possible. If both skippers do that, it opens up a safe passage, normally. Do NOT anchor in the narrow channel (in any event, it is a violation of Federal Regulations to anchor in any channel or tie up to any federal buoy.)
Do not cross the channel if it will interfere with a vessel that, by the nature of their draft, is confined to it. Rule 9(b) specifically states that “a vessel less than 20 meters (~60 feet) in length shall not impede the passage of a vessel which can safely navigate only within the narrow channel or fairway.” In contrast, a large vessel should not try to pass a smaller vessel in a narrow channel as the hydrodynamic effects caused by the larger displacement and the suction of her propellers will pull the smaller vessel into the larger one. That would be a very bad day… (see section on "Sucked In" under #COLREGs-Rule2)