Does Port Starboard Apply when Rule 18 Applies?

Does Port Starboard Apply i.e. Rule 10 apply when Rule 18 Applies is a question that seems to come up quite regularly at club level sailing and last Sunday was just such an occasion.

The Scenario

Two boats on a RUN approach a mark for a STARBOARD ROUNDING . At four boat lengths the inside boat enters the ZONE, on PORT, calls for water. The outside boat calls STARBOARD and adds the call NO WATER.

The Rule

18.1 When Rule 18 Applies

Rule 18 applies between boats when they are required to leave a mark on the same side and at least one of them is in the zone.

However, it does not apply

(a) Between boats on opposite tacks on a beat to windward,

(b) Between boats on opposite tacks when the proper course at the mark for one but not both of them is to tack,

© Between a boat approaching a mark and one leaving it, or

(d) if the mark is a continuing obstruction, in which case rule 19 applies.

Check List

Running through the check list effectively created by 18.1:-

(a) No – Boats are not on a Beat to Windward

(b) No - Boats will not be tacking – they will GYBE

© No – Both boats are approaching the Mark

(d) No – The mark is not a CONTINOUS OBSTRUCTION

So Rule 18.1 must apply.

However, unlike in Rule 19 where it is specifically stated that:-

While the boats remain overlapped, she shall keep clear and rules 10 and 11 do not apply.

There is no such stamen in rule 18.2

So does the STARBOAD CALL have any validity? i.e. Does Rule 10 still apply ?

Clearly the PORT tack boat will have to Gybe in order to round the mark at some stage but until then is he at the mercy hands of the STARBOAD boat.

And can he, as the INSIDE BOAT, take his mark room.

Well What do you think ??

First, R 19 says that it does not apply to an obstruction that is also a mark. So at a mark, R 18 applies and not R 19.

R 18 is in Section C. R 10 is in section A. The preamble for the Rules says

A boat has right of way over another boat when the other boat is

required to keep clear of her. However, some rules in Sections B, C

and D limit the actions of a right-of-way boat.

Mark Room is not a ROW rule. They are in Section A. So the boat with ROW, still has ROW, but may be limited by other rules. Mark room does not confer ROW, its just means that another boat, including a ROW boat has to give you room.

So R 10 applies as well as R 18. The inside Port boat with mark room is entitled only to enough room to round the mark, and that includes room to gybe if required. So Port cannot force Stbd out wider to allow Port to go in wide and out close.

So once Mark room is established - ie as soon as the bow of the first boat touches the zone, then the boat with mark room is allowed to sail their proper course.

So Stbd cannot interfere with port's proper course. The hail of stbd may remind Port of the presence of a ROW stbd boat, and to sail with only the minimum of room.

John

So let me get this right John,

In the Zone the inside boat having established an Overlap has Mark Room and a Starboard Tack Boat cannot deny Mark Room on the basis that the Inside boat is on a Port Tack.

When :- Not on a beat to windward i.e. a Run – the Leeward Mark or a Gybe Mark.

So effectively Rule 10 and all the rules of Section A do not apply when Rule 18 applies

.

No Dave, not correct. All the rules of Part A (R 10 through 13) apply at a mark. However R 18 may place a restriction on how far they may push.

So the Port gybe inside overlapped boat with mark room cannot swing wide going into the mark, as the stbd gybe boat has ROW. The Stbd boat cannot force the inside port boat to hit the mark or pass on the wrong side.

Now reverse the situation to a Port rounding. The now-inside STBD boat can push out wide and the port gybe must keep clear (R10). However, if it is is not a gate mark, then Stbd needs to be aware of R 18.4 and not sail further from the mark.

So in the second case, STBD as ROW and inside boat can make a 'tactical rounding' - in wide , out close. But in the first case, the port gybe boat cannot as they have no right to push STBD out wide - they must keep clear of stbd (R10). So in each case, STBD as ROW gets to control the track around the mark.

John