rule 12 - sailing vessels

7/24/2019 Rule 12 - Sailing Vessels

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Rule 12 - Sailing vessels

(a) When two sailing vessels are approaching one another, so as to involve riskof collision, one of them shall keep out of the way of the other as follows:

(i) when each has the wind on a different side, the vessel which has the

wind on the port side shall keep out of the way of the other;

(ii) when both have the wind on the same side, the vessel which is to

windward shall keep out of the way of the vessel which is to leeward;

(iii) if a vessel with the wind on the port side sees a vessel to windward andcannot determine with certainty whether the other vessel has the wind

on the port or on the starboard side, she shall keep out of the way of the

other.

(b) For the purpose of this Rule the windward side shall be deemed to be the

side opposite to that on which the mainsail is carried or, in the case of a

square-rigged vessel, the side opposite to that on which the largest fore-and-aft sail is carried.

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Rule 12 - Sailing vesselsTall ships

tallships.org 2


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Sailing yachts

mellowdolphin.com3


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Sailing yachts

mellowdolphin.com

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General

Factors to consider if risk of collision exists:

!The point of sailing (the tack)

!The windward and leeward side

!The windward and leeward vessel

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Rule 12 - Sailing vesselsPoint of sailing

Side on which a vessel catches the wind

cruise-charter.net

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Rule 12 - Sailing vesselsMain points of sailingPort tack: the wind is on the port side and the sails are over the starboard

side

Starboard tack:the wind is on the starboard side and the sails are over

the port side

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Rule 12 - Sailing vesselsPort tack

bluecruiseyachtcharters.com 8


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Starboard tack

cyrg.com 9


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Main points of sailing

A sailing vessel can be on port tack and sail:

! clause hauled

! clause reaching

! beam reaching

! broad reaching! running

The same applies to starboard tack

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Close hauled

freespace.virgin.ne 11


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Rule 12 - Sailing vesselsClose reaching

macgregor26.com 12


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morebutter.com

Close reaching

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Beam reaching

sailing.about.com 14


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Rule 12 - Sailing vesselsBroad reaching

sailing.about.com

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Running

macgregor26.com

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General

freepages genealogy

Main types of rigging

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General

freepages genealogy


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Main sail and jib


boatnorth.com 19

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Main sail and genoa


boatnorth.com 20

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Mizen


cheoylee41.com 21

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Spinnaker sailing

spinnaker-sailing 01


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Windward and leeward side of vessel

Windward side: the side exposed to the windLeeward side: side opposite to the side exposed to the wind

Windward side

Leeward side

The windward side is also defined as the side opposite to the main sail side

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Windward and leeward vessel

Windward vessel

Leeward vessel 24


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Rule 12 - Sailing vesselsThe port and starboard tack rule Rule 12 (a) (i)

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Both vessels have the wind on a different sideVessel A, which has the wind on her port side (the port tack vessel)

must keep out of the way of vessel B (the starboard tack vessel)

A B

Vessel A can alter course to starboard or to port, dependent on the wind direction

Vessel A shall take early and substantial action. Vessel B keeps her course andspeed

If vessel A passes on the port side of vessel B she shall pass at a rather largedistance not to fall without wind when abeam of B

Rule 14, Head-on situation does not apply to sailing ships 26

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Rule 12 - Sailing vesselsThe windward and leeward rule Rule 12 (a) (ii)

A

B

Both vessels have the wind on the

same side (Both are port tack vessels)

Vessel A is the windward vessel andmust take avoiding action if there is risk

of collision

Vessel A must take early and substantial

action

Vessel A shall avoid crossing vessel Bs

course and also avoid to cut her wind

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Rule 12 - Sailing vesselsThe windward and leeward rule Rule 12 (a) (ii)

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The port tack rule for doubtful cases Rule 12 (a) (iii)

B

A

Vessel A has the wind on the

port side and sees vessel B to

windward.

Vessel A cannot see withcertainty whether vessel B has

the wind on the port or on the

starboard side.

Vessel A shall, according to Rule12 (a) (iii), keep out of the way

of vessel B

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Rule 12 - Sailing vesselsSailing vessels overtaking Rule 13 (a)

In accordance with Rule 13, any vessel overtaking another vesselmust keep clear of the other vessel.

Hence, a sailing vessel overtaking another sailing vessel must keep

clear of the other sailing vessel.

Rule 13 overrides Rule 12

A

B

Although both vessels are on port tack, vessel A is faster than vessel B and thusovertaking vessel B. Besides, vessel A is in the overtaking sector of vessel B

Conclusion: vessel A must keep clear of vessel B 31


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! Windward side according to par. 12(b)

Side opposite to mainsail OR

For square-rigged vessel: side opposite to largestfore-and-aft sail

! Windward vessel

Vessel from which the wind is blowing

! Leeward vessel

Vessel toward which the wind is blowing

Summary

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! Port and starboard tack rule

The port tack vessel keeps out of the way of

the starboard tack vessel

! Windward and leeward rule

The vessel to windward shall keep out of the

way of the vessel which is to leeward

! Port tack rule in case of doubt

The port tack vessel shall keep out of the way

Summary

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Additional literature

More details can be found in the following textbook:

International Regulations for Preventing Collisions atSea by Capt. Pierre Deseck, Master mariner, M.Sc., FNI

The textbook can be bought online at the following address:

http://maritimeknowhow.com. Just click on books for details

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rule 12 - sailing vessels

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