Size and sail matters

The old adage, ‘Power gives way to sail’, works most of the time but can sometimes get a skipper into trouble. It is a reasonable statement, because in open water for much of the time, a power driven vessel would keep clear of a sailing vessel. But there are many times when this may not be the case.

There are also times when a vessels size defines what she must do in a situation between two vessels. Quite often, the regulations usually kick in for vessels under 20m. Let’s examine a few cases: Please note that these are just excerpts of the rules and the full regulations should be read for a fuller understanding.

Rule 9

Narrow Channels
(b) A vessel of less than 20 meters in length or a sailing vessel shall not impede the passage of a vessel which can safely navigate only within a narrow channel or fairway.

The term narrow channel or fairway is dependent upon the vessel using it. Sometimes a harbour byelaw will advise what size of vessel will be termed as one that can only navigate within the channel, although common sense should prevail.

Rule 10

Traffic Separation schemes
(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.

This means that a power driven vessel under 20m or sailing vessel should take early action to allow sufficient sea room to the other vessel. This rule does not overrule the fact that both vessels still have to avoid a collision at the end of the day.

Rule 13

Overtaking
(a) Notwithstanding anything contained in the Rules of Part B, Sections I and II, any vessel overtaking any other shall keep out of the way of the vessel being overtaken.

A sailing boat or any other vessel overtaking another boat shall keep out of the way of the vessel being overtaken.

Rule 18

Responsibilities between vessels
A power-driven vessel underway shall keep out of the way of:

I.a vessel not under command;
II.a vessel restricted in her ability to manoeuvre;
III.a vessel engaged in fishing;
IV.a sailing vessel.

A sailing vessel under way shall keep out of the way of:

I.a vessel not under command;
II.a vessel restricted in her ability to manoeuvre;
III.a vessel engaged in fishing;

This is where the power gives way to sail statement comes from, but you can see a sailing vessel needs to keep out of the way of three types of vessel and a power driven vessel has even more to keep clear.

Rule 19

Conduct of vessels in restricted visibility
This rule applies to vessels not in sight of one another when navigating in or near an area of restricted visibility.

When in restricted visibility, special rules apply and the requirements to avoid a collision are no longer a power over sail question, they have to comply with this rule.

Conclusion

There are many instances within the International Regulations for the Prevention of Collisions at Sea when the size or type of vessel come into play.

Take a look at the RYA International Regulations for Preventing Collisions at Sea to update your knowledge.

Buy RYA International Regulations for Preventing Collisions at Sea at the RYA Shop

Written by: Simon Jinks, Yachtmaster Instructor Examiner