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bullseye 06-10-2002 09:59 PM

collision course - Tip
heres a little tip i learned a long time ago from a teacher while i did a basic beginners sailing course,ive done other more advanced courses since then but never heard this tip since, in any of the latter courses.

its only applicable for sailing in lakes,rivers ,harbours.

if you think your on a collision with another vessel,look at the land behind the other vessel,if the vessel is moving forward in relation to the land behind it,it''ll pass in front of you.

if it appears it''s going backwards in relation to the land behind it(you know the vessel is actually going forward),it''ll pass behind you.

if it appears to be staying stationary in relation to the land behind it,your on a collision course.

just a quick method that takes only seconds,of course this method assumes both vessel holds its course & speed,both of which can change at any time.

Denr 06-11-2002 12:35 PM

collision course - Tip
How about if you’re outside the sight of land? The answer is: take a compass bearing on the other vessel. If the angle decreases, the other vessel will pass in front of you, if the angle decreases, you will pass in front of the other vessel. If speed changes on either vessel the angles will change and the stand-on vessel will be determined according to the pecking order and right-of way-rule.

Pecking order:
Vessel not in command
Vessel restricted in her ability to manuver
Fishing (commercial)
Sailboats(sailing) not under power

In all circumstances, it is incumbent on the skipper to maintain a look out at all times and to observe the rules of right-way as they pertain to the type of vessels involved in the crossing situation.

maxcontax 01-01-2003 06:11 AM

collision course - Tip
We were taught to close one eye, extend an arm and hold a finger on the subject vessel and then freeze. If the vessel retreats from the finger you will pass forward, if it advances from the finger you will pass aft, and if the vessel remains on the finger, you are on a collision course.
The method works anywhere at any angle or speed.

c172guy 01-02-2003 08:06 AM

collision course - Tip
The relative bearing of the other boat is what I use. If the bearing is constant you are traveling the same course and speed or are on a collision course. Since it is rare to be traveling the same course and speed a constant bearing usually means collision!!! For a bearing I usually pick a point on my boat and use that as a reference. The handheld compass is the best method but usually it is obvious.
I have a question about the right of way rules. Some postings seem to idicate that the stand-on vessel has options as to standing on or not. As I understand the rules standing on is not an option. If you are the stand on vessel and your course change causes an accident you are responsible. Basically the rules are designed so that boats know what other boats will do. This way a passing boat knows that you will hold course so that they know the safest way to pass. A ship knows that a daysailer won''t cut across the channel. Kinda like you know a car will stop at a red light or that a car won''t make a left hand turn in front of you. My reasonong is that a sailboat is not allowed to tack across the front of a passing boat even if it means luffing the sails.

DuaneIsing 01-03-2003 02:47 AM

collision course - Tip

As to your question about the "stand on" vessel, I agree that it is intended so that the "give way" vessel can have some degree of confidence in you maintaining your present course and speed. I have had a number of circumstances where I was tacking up a narrow waterway in an engineless sailboat (to stay in adequately deep water), and had other boats approach from the opposite direction.

In general, I continued my necessary tacking manuevers during the approach of the other boats (let''s limit it to powerboats to keep it simple), but as we drew closer, I would try to ensure that I would not have to tack into the approaching boat''s path. I can recall times when I was faced with the choice of: maintaining speed which would force me to tack too close to the approaching boat, running aground, or slowing somewhat so I could remain on my current tack until after the other boat passed. I always chose the last option.

Technically, I failed to maintain both course and speed, but it seems like the best option. Any better ideas or comments?


Jeff_H 01-03-2003 03:54 AM

collision course - Tip
I believe that Duane''s post brings up an important point. Under COLREGS The obilgations of the stand-on vessel are as follows:

(ii) The latter vessel (Stand-on)may however take action to avoid collision by her maneuver alone, as soon as it becomes apparent to her that the vessel required to keep out of the way is not taking appropriate action in accordance with these Rules.

(b) When, from any cause, the vessel required to keep her course and speed finds herself so close that collision cannot be avoided by the action of the give-way vessel alone, she shall take such action as will best aid to avoid collision.

In other words, a stand on Vessel is actually allowed to alter course to avoid collision if it is done in a manner that should be obvious to the other vessel. In the case cited by Duanne, by heading up and slowing down to delay a tack, as stand on vessel you have actually done the right thing. COLREGS further lists the following permitted alterations in course to avoid collision;

(c) If there is sufficient sea room, alteration of course alone may be the most effective action to avoid a close-quarters situation provided that it is made in good time, is substantial and does not result in another close-quarters situation.

(d) Action taken to avoid collision with another vessel shall be such as to result in passing at a safe distance. The effectiveness
of the action shall be carefully checked until the other vessel is finally past and clear.

(e) If necessary to avoid collision or allow more time to assess the situation, a vessel may slacken her speed or take all way off
by stopping or reversing her means of propulsion.


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