Rules of the Road Introduction

The primary role of the rules of the road, is to prevent accidents and collisions. The rely on common sense and application by all users, to succeed. The rules are a bit wordy so the rules are stated with summary in general speak. Safe passage is the responsibility of EVERYONE.

Traffic separation schemes may be adopted by the Organization for the purpose of these Rules.

Notes

Rule 1

Many harbour authorities have local regulations which apply within their harbour limits. These concern such things as special local sound signals for vessels maneuvering, and priorities for vessels bound inward or outward. The Admiralty Sailing Directions which are brought up to date every 18 months or so by the issue of a supplement give details of most local regulations and should be consulted before entering an unfamiliar harbour.
The special signals referred to under Rule 1 (c) are not often encountered but details of those which exist will be found in the annual summary of Admiralty Notices to Mariners.
Traffic separation schemes are becoming an increasingly important feature in the regulation and control of shipping movements and are therefore specifically referred to under Rule 1 (d). The lanes and zones which make up separation schemes are shown on the Admiralty charts of the areas in which they are in operation.
Many warships, for example, carry either fewer lights than are required or lights which are positioned in an unusual way. A submarine carries its steaming lights much lower than a vessel of her size is required to do by the regulations and at night this gives the impression that she is much farther away than she actually is. Other classes of warship carry steaming lights very close together which makes it extremely difficult to judge their aspect. The existence of these unusual lights means that assumptions must not be made simply from the appearance of another ship's lights.

Rule 3

General Definitions

For the purposes of these Rules, except where the context otherwise requires:

3 (g)

The term "vessel restricted in her ability to manoeuvre" means a vessel which from the nature of her work is restricted in her ability to manoeuvre as required by these Rules and is thereore unable to keep out of the way of another vessel.

The term "vessels restricted in their ability to manoeuvre" shall include but not be limited to:

This is one of the most important Rules. If not observed, the rest of the Rules might as well not exist.
In a sailing yacht there are two potential blind arcs, on the lee bow and directly to windward. Low-clewed, long-footed headsails create a very large blind arc. Even a relatively high-clewed sail can have a similar effect when the yacht is well heeled. This blind arc is worst for crew members sitting to windward in the cockpit.
          The windward blind arc only exists in strong winds when the spray and rain sting the eyes. It is painful to look directly up-wind in a blow. Even the best designed oilskins will not keep the spray out in a ful frontal attack, so the natural instict to stay dry does not encourge a good watch to windward. Oilskin hoods do not help much; if they are loose fitting enough to be comfortable they will not turn with the head. Looking over one's shoulder for a quick glance up-wind results only in a close-up view of the inside of the back of the hood!
The old fashioned sou' wester with a huge flap at the back may not be quite as waterproof, but it does have the great practical advantage of turning in unison with the wearer's head. Its practical advantages probably outweigh its sartorial inelegance and combined with a high collar and neck towel, it allows an efficient lookout without getting too wet.

Motor yachts and moter sailers with enclosed steering positions enable a lookout to be kept in much greater comfort but hte structure which provides the shelter creates its own blind arcs. These are particularly dangerous if the crew in the wheelhouse sit or stand in the same position for long periods. By doing so they run the risk of allowing another ship to approach on a steady bearing, and therefore a collision course, without being sighted.

          To keep an effective lookout at night, “night vision” is needed. The human eye takes a considerable time to adapt to darkness after it has been exposed to white light. The actual time varies from one individual to another, but on average it takes about fifteen minutes, after exposure to white light of normal domestic intensity, before eyesight is fully effective in near darkness. To overcome this problem the accomodation and chart table should be lit by red lights at night. A red light does negligible damage to night vision and is much more restful to the eyes. Similarly, the use of searchlights and bright deck working lights should be kept to a minumum. Both are essential for certain operations, but a searchlight is particularly dangerous for two reasons. If it is inadvertantly directed into another vessel's cockpit or wheelhouse it can cause sudden and unexpected night blindness to her crew. If its beam is relied on to pick up unlit navigational marks, the lookouts may see the marks which they are looking for quite clearly but, at the same time, fail to see other small boats or obstructions because their eyesight has been adversly affected by the use of the searchlight in the first place.
          Smokers are always a potential hazard to night vision, the flare of a match or lighter being bright enough to cause loss of adaptation to anyone in the wheelhouse or cockpit who looks directly at it. If you smoke, warn the rest of the watch before you light up, and close one eye yourself to save its night-vision.
          A good listening watch is particularly important in conditions of poor visibility. It is impossible to listen effectively from inside a closed wheelhouse and, in fog, at least one of the watch should be stationed on the open deck. In many sailing yachts the noise fo the auxiliary engine is loud enough to mask any sounds from outbouard. If this is the case the engines should be slowed or even stopped for two minutes in five to allow an efficent listening watch to be kept.

Notes

Rule 7

This is the first rule which is driectly concerned with collision avoidance. whenever a situation arises in which two ships approach, the maste of each has to answer two questions. Is there a risk of collision in this situation? If so, what action should I take to avoid it? This rule gives guidelines on answering the first question.
        Any collision situation poses a problem of relative volocities. If the relative movement of the two ships is directly towards each other then, unless one of them alters course, they will collide. This situation is easily identified because when it exists the compass bearing of one ship from the other remains steady. A typical collision situation is shown in the diagram below (Fig 1). The compass bearing of ship B from ship A remains steady at 045° as they close. In this particular case, the relative bearing of B from A also remains on a steady course. If, in this situation, A had been steered erratically, yawing 10° either side of here mean course, the relative bearing of B would have altered through 20° as she closed. The compass bearing, however would have altered very little and the collision would still have happened.

Rule 7
Fig 1

Notes

8

Make a large enough alteration of course for your intentions to be absolutely clear.

Note 8

          For an alteration of course to be absolutely obvious, particulary at night, it should involve presenting a totally different “aspect” to the other ship. In Rule 8 Fig 3 (a) the alteration between A1 and A2 is probably sufficient to avoid a collision but, throughout the manoeuvre, A continues to present here starboard bow, or by night her starboard side light, to B. In Rule 8 Fig 3 (b), however, the alteration between A1 and A2 is large enough to present a totally diffent aspect and it is abundantly clear to B that A has altered course to pass under here stern.

Note
8

Inshore traffic zones shall not normally be used by through traffic which can safely use the appropriate traffic lane within the adjacent traffic separation scheme.
However, vessels of less than 20 metres in lenght and sailing vessels may under al circumstances us einshore traffic zones.

A's course made good is at right angles to the traffic flow and she presents a quarter aspect to ships following the lane.
B's heading is at right angles to the traffic flow and she presents a true 90 crossing aspect to ships following the lane. B's time of crossing the lane is shorter than A's.