- Clarification of the definition "Vessel constrained by her draught", Rule 3 (h)
Not only the depth of water but also the available navigable water width should be used as a factor to determine whether a vessel may be regarded as constrained by her draught. When determining this, due account should also be taken of the effect of a small underkeel clearance on manoeuvrability of the vessel and thus her ability to deviate from the course she is following. A vessel navigating in an area with a small underkeel clearance but with adequate space to take avoiding action should not be regarded as a vessel constrained by her draught.
- Clarification of the application of the word "underway", Rule 3 (i)
When applying the definition of the term "underway" marinors should also have regard to Rule 35 (b) where it is indicated that a vessel may be underway but stopped and making no way through the water.
- Clarification of the implication of the words "not to impede" as appearing in Rules 9 (b), (c) and (d), 10 (i) and (j) and 16 (d)
When a vessel is required not to impede the passage of another vessel, such vessel shall so far as practicable navigate in such a way as to avoid the development of risk of collision. If, however, a situation has developed so as to involvo risk of collision, the relevant Steering and Sailing Rules shall be complied with.
- Clarification of the relation between Rule 10 and the Rules of Part B, Sections II and III
A vessel navigating in or near a traffic separation scheme adopted by the Organization shall, in particular, comply with Rule 10 of the International Regulations for Preventing Collisions at Sea, 1972, to minimize the development of risk of collision with another vessel. The other Rules of the 1972 Collision Regulations apply in all respects, and particularly the Rules of Part B. Sections II and III, if risk of collision with another vessel is deemed to exist.
- Clarification of the transference within a lane Rule 10 (b) (i)
It is within the ordinary practice of prudent seamanship and in keeping with the provisions of Rule 10 of the 1972 Collision Regulations that a vessel using a traffic lane may make a transfer within a lane from one side to the other, provided such a transfer is accomplished at as small an angle to the general direction of traffic flow as is practicable.
- Clarification on the use of inshore traffic zones by small vessels, Rule 10 (d)
To comply with Rule 10 (j) and for reasons of sate navigation a vessel of less than 20 metres in length or a sailing vessel, even when through traffic, may use inshore traffic zones.
- Clarification of the relation between Rule 18 (d) and the Rules of Part B, Sections II and III
A vessel constrained by her draught shall, when risk of collision with another vessel in a crossing or head-on situation exists, apply the relevant Stoering and Sailing Rules as a power-driven vessel. She should, when showing the signals prescribed by Rule 28, have her engines ready for immediate manoeuvre and proceed at a safe speed as required by Rule 6.
