boats.com - Rules and Regulations: Navigational Rules

Rule 4
The International Rules divide Part B - Rules 4 through 19 - into three "Sections"; the Inland Rules uses the term "Subparts" for these subdivisions. There is no practical effect in the use of these different titles. The Rules of Section/Subpart I - Rules 5 through 10 - are applicable in conditions of both normal and restricted visibility.

Every vessel shall at all times maintain a proper lookout by sight and hearing as well as by all available means appropriate in the prevailing circumstances and conditions so as to make a full appraisal of the situation and of the risk of collision.

Rule 5
This is a basic Rule, the violation of which is so often the cause of small-craft accidents - collisions with other boats or stationary objects. On smaller vessels, the "lookout" is nominally the helmsman, and this is acceptable if he is aware of his responsibility and performs his duties. He must be able to hear as well as see potential dangers. If in doubt, a skipper should post an additional person with the sole duties of lookout; this is particularly necessary in situations of reduced visibility. It is even possible that two lookouts will be necessary - one forward and one aft. Should a collision occur, failure to have a proper lookout would be strongly held against you in court.

This is also the Rule that is obviously violated by all single-handing skippers on long voyages, or even on voyages of more than a few hours. Note that the Rule states that a lookout is required "at all times" - this includes when a vessel is at anchor.

Every vessel shall at all times proceed at a safe speed so that she can take proper and effective action to avoid collision and be stopped within a distance appropriate to the prevailing circumstances and conditions. In determining a safe speed the following factors shall be among those taken into account:

(i) the state of visibility
(ii) the traffic density, including concentrations of fishing vessels or any other vessels;
(iii) the maneuverability of the vessel with special reference to stopping distance and turning ability in the prevailing conditions;
(iv) at night, the presence of background light such as from shore lights or from back scatter of her own lights;
(v) the state of wind, sea, and current, and the proximity of navigational hazards;
(vi) the draft in relation to the available depth of water.

(i) the characteristics, efficiency and limitations of the radar equipment;
(ii) any constraints imposed by the radar range scale in use;
(iii) the effect on radar detection of the sea state, weather, and other sources of interference;
(iv) the possibility that small vessels, ice and other floating objects may not be detected by radar at an adequate range;
(v) the number, location, and movement of vessels detected by radar;
and
(vi) the more exact assessment of the visibility that may be possible when radar is used to determine the range of vessels or other objects in the vicinity.

Rule 6
This is another basic Rule - so obvious that it shouldn't need comment. But note that no specific speed is stated in terms of knots or miles per hour. The sole focus is on preventing collisions, and a "safe speed" will be determined by the prevailing conditions, with six common sense factors specifically listed. (Numerical speed limits found in some harbors and waterways are not part of the Navigation Rules; they must not be exceeded, and under some conditions may actually be greater than a "safe speed.") Note that this Rule is applicable in all conditions of visibility -- normal and restricted.

If you have radar on your boat, and you are using it, you are responsible for using it properly - too many small-craft skippers do not know how to plot radar targets. Learn the capabilities and limitations of your radar set and how to meet the legally required determination of risk of collision. The commonly used phrase of "stopping in half of the distance of visibility" does not appear in the Rules and is not applicable in many cases, such as when radar is being used.

(a) Every vessel shall use all available means appropriate to the prevailing circumstances and conditions to determine if risk of collision exists. If there is any doubt such risk shall be deemed to exist.
(b) Proper use shall be made of radar equipment if fitted and operational, including long-range scanning, to obtain early warning of risk of collision and radar plotting or equivalent systematic observation of detected objects.
(c) Assumptions shall not be made on the basis of scanty information, especially scanty radar information.
(d) In determining if risk of collision exists, the following considerations shall be among those taken into account:

(i) such risk shall be deemed to exist if the compass bearing of an approaching vessel does not appreciably change; and
(ii) such risk may sometimes exist even when an appreciable bearing change is evident, particularly when approaching a very large vessel or a tow or when approaching a vessel at close range.

Rule 7
Radar is fine if you have it and use it correctly, but it is not essential to the determination of "risk of collision." The very basic means is by visual observation - a "seaman's eye." Early on, establish a compass bearing to the other vessel, and re-measure it at frequent intervals - if it doesn't change, with neither vessel maneuvering, there is real risk of collision. Even if it does change, there is still a possible risk, especially if the other vessel is a tug towing a barge astern - never try to pass between a tug and its tow!

(a) Any action taken to avoid collision shall, if the circumstances of the case admit, be positive, made in ample time and with due regard to the observation of good seamanship.
(b) Any alteration of course or speed to avoid collision shall, if the circumstances of the case admit, be large enough to be readily apparent to another vessel observing visually or by radar; a succession of small alterations of course or speed should be avoided.
(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 shall slacken her speed or take all way off by stopping or reversing her means of propulsion.
(f)

(i) A vessel which, by any of these rules, is required not to impede the passage or safe passage of another vessel shall, when required by the circumstances of the case, take early action to allow sufficient sea room for the safe passage of the other vessel.
(ii) A vessel required not to impede the passage or safe passage of another vessel is not relieved of this obligation if approaching the other vessel so as to involve risk of collision and shall, when taking action, have full regard to the action which may be required by the rules of this part.
(iii) A vessel, the passage of which is not to be impeded, remains fully obliged to comply with the rules of this part when the two vessels are approaching one another so as to involve risk of collision.

Rule 8
Another very logical Rule, but one that is often slighted. If you are approaching another vessel and some action is required of you, such as a change of course or speed, make it soon enough to be effective, and make it of sufficient size to be apparent to the other skipper. From a distance, a change of course is usually more apparent than a change of speed, but don't hesitate to slow down or stop if this is required for safety. Slowing down has the added advantage of giving you more time to assess the situation. The phrase "all way off" means dead in the water without forward movement -- no "coasting."

(i) A vessel proceeding along the course of a narrow channel or fairway shall keep as near to the outer limit of the channel or fairway which lies on her starboard side as is safe and practicable.
(ii) Notwithstanding paragraph (a)(i) and Rule 14(a), a power-driven vessel operating in narrow channels or fairways on the Great Lakes, Western Rivers, or waters specified by the Secretary, and proceeding downbound with a following current shall have the right-of-way over an up-bound vessel, shall propose the manner and place of passage, and shall initiate the maneuvering signals prescribed by Rule 34(a)(i), as appropriate. The vessel proceeding upbound against the current shall hold as necessary to permit safe passing.

(b) A vessel of less than 20 meters in length or a sailing vessel shall not impede the passage of a vessel that can safely navigate only within a narrow channel or fairway.
(c) A vessel engaged in fishing shall not impede the passage of any other vessel navigating within a narrow channel or fairway.
(d) A vessel shall not cross a narrow channel or fairway if such crossing impedes the passage of a vessel which can safely navigate only within that channel or fairway. The latter vessel shall use the danger signal prescribed in Rule 34(d) if in doubt as to the intention of the crossing vessel.
(e)

(i) In a narrow channel or fairway when overtaking, the power-driven vessel intending to overtake another power-driven vessel shall indicate her intention by sounding the appropriate signal prescribed in Rule 34(c) and take steps to permit safe passing. The power-driven vessel being overtaken, if in agreement, shall sound the same signal and may, if specifically agreed to take steps to permit safe passing. If in doubt she shall sound the danger signal prescribed in Rule 34(d).
(ii) This Rule does not relieve the over-taking vessel of her obligation under Rule 13.

(f) A vessel nearing a bend or an area of a narrow channel or fairway where other vessels may be obscured by an intervening obstruction shall navigate with particular alertness and caution and shall sound the appropriate signal prescribed in Rule 34(e).
(g) Every vessel shall, if the circumstances of the case admit, avoid anchoring in a narrow channel.

Rule 9
This is basically the waterborne equivalent of driving on the right-hand side of the road. The needs of a vessel that must have the available deeper water are protected.

The term "narrow" should be construed with respect to the size of the vessels using the waterway.

A vessel required to "not impede" should take early action to keep clear of the other vessel by a wide margin. This might be a vessel that otherwise would be the "stand-on" vessel, but whose status is changed by the practical considerations of Rule 9.

Sound signals are required, but under different circumstances in the International and Inland Rules.

On the Great Lakes, Western Rivers - essentially the Mississippi River and its tributaries - and other specified waters, the Inland Rules specifically provide privileged status to a vessel proceeding with the current. In other areas that may have tidal currents or normal river flows, this Rule does not apply, but common courtesy should lead to giving a vessel going with the current, and thus being less maneuverable, the right-of-way over a vessel opposing the current flow.

In Rule 9(d), the Inland Rules require the whistle signal of doubt or danger - five short blasts sounded rapidly. Under the International Rules, this signal is optional. The "bend" signal of one prolonged blast is also used by vessels entering a waterway from a side channel or coming out of a berth or slip; see Rule 34(g). Note that the Rules do not provide for a "long" blast, only short blasts (approximately one second) or prolonged blasts (four to six seconds duration).

In October, 1996, Inland Rule (e)(i) was changed to limit its provisions to power-driven vessels. Its wording does not parallel that of the corresponding International Rule.

(a) This Rule applies to traffic separation schemes and does not relieve any vessel of her obligation under any other Rule.
(b) A vessel using a traffic separation scheme shall:

(i) proceed in the appropriate traffic lane in the general direction of traffic flow for that lane;
(ii) so far as practicable keep clear of a traffic separation line or separation zone;
(iii) normally join or leave a traffic lane at the termination of the lane, but when joining or leaving from either side shall do so at as small an angle to the general direction of traffic flow as practicable.

(c) A vessel shall so far as practicable avoid crossing traffic lanes, but if obliged to do so shall cross on a heading as nearly as practicable at right angles to the general direction of traffic flow.
(d)

(i) A vessel shall not use an inshore traffic zone when she can safely use the appropriate traffic lane within the adjacent traffic separation scheme. However, vessels of less than 20 meters in length, sailing vessels and vessels engaged in fishing may use the inshore traffic zone.
(ii) Notwithstanding subparagraph (d)(i), a vessel may use an inshore traffic zone when en route to or from a port, offshore installation or structure, pilot station, or any other place situated within the inshore traffic zone, or to avoid immediate danger.

(e) A vessel other than a crossing vessel or a vessel joining or leaving a lane, shall not normally enter a separation zone or cross a separation line except:

(f) A vessel navigating in areas near the terminations of traffic separation schemes shall do so with particular caution.
(g) A vessel shall, so far as practicable, avoid anchoring in a traffic separation scheme or in areas near its terminations.
(h) A vessel not using a traffic separation scheme shall avoid it by as wide a margin as is practicable.
(i) A vessel engaged in fishing shall not impede the passage of any vessel following a traffic lane.
(j) A vessel of less than 20 meters in length or a sailing vessel shall not impede the safe passage of a power-driven vessel following a traffic lane.
(k) A vessel restricted in her ability to maneuver when engaged in an operation for the maintenance of safety of navigation in a traffic separation scheme is exempted from complying with this Rule to the extent necessary to carry out the operation.
(l) A vessel restricted in her ability to maneuver when engaged in an operation for the laying, servicing or picking up of a submarine cable, within a traffic separation scheme, is exempted from complying with this Rule to the extent necessary to carry out the operation.

Rule 10
Obviously, the International Rule is much more specific about proper behavior regarding Traffic Separation Schemes than the Inland Rule.

This is an important rule and there are two aspects of it that are particularly critical to smaller vessels. First, all crossing vessels must cross on a heading as nearly as practicable at right angles to the lane, thereby presenting a full profile to vessels using the lane.

Second, a vessel - even if under sail - is required "not to impede the safe passage of a power-driven vessel following a traffic lane." The aim should be to cross as quickly as possible, which means using the engine when necessary and not trying to counteract any sideways effect of the tidal stream.

In the illustration at upper right, Yacht A is counteracting the effect of the tidal stream to make her track at 90° to the lane, but her profile to vessels in the lane is considerably reduced. This has two results. First, her time in crossing the lane is much increased; second, her reduced profile means that she is less visible, both visually and on radar screens, than if she presented a full profile. The action taken by Yacht A is incorrect. Yacht B is correctly presenting her full profile in the lane and is not attempting to counteract the tidal stream. Although her track is longer than that of Yacht A, she will cross in less time. This is the correct procedure.

Also illustrated is the fact that there is a blind area ahead of and on each bow of any vessel - the larger the vessel the larger the blind area. As a general guideline, if you are within a mile of a medium-to-large vessel, i.e. 10,000 to 15,000 tons, then you are in the blind arc. A simple test: If you cannot see the captain's bridge, then the chances are the captain cannot see you.

Avoid either remaining in, or crossing the bow within, the blind arc. The actual area of the arc is a function of the size of the vessel, the size of the yacht, the height of eye of the vessel, and its beam. It is the yacht hull that has to be seen, not the mast.

Inland Navigation Rules