A guest post by Mike ButterfieldI have been reflecting on the position of the boat giving mark room as has been discussed. A lot of friends have shared their thoughts with me and I am revisiting the position.
The simple one first!
On leeward marks.
Generally RRS 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.
When does it end?
Clearly the right to mark room has ended when both have left the zone but in reality it ends when the boat entitled to mark room has been able to sail her proper course at the mark. See Definition of mark room.
If this is when it applies, are the relationships between the boats changeable?
Well no not really once the relationship is established it remains, 18.2(c) even if later an overlap is broken or a new overlap begins.
The exception is when the boat entitled to mark room leaves the zone or if either boat passes head to wind.
In this circumstance we rely on 18.2(a) unless the circumstances for 18.2(b) become applicable again. Here basically an inside overlapped boat is entitled to mark room.
What is mark room?
Well it is a two sided advantage.
Initially Room to sail to the mark. I look on this as giving the boat a corridor of opportunity. If it stays in that corridor (even if give way) it is protected. The protection is in 18.5, this is protection from breaking a rule of section A.
If she strays out of the corridor and the Right of Way boat has to take avoiding action then she has taken too much room and is subject to a penalty as the exoneration is not available. Just as before I believe if the right of way boat freely gives additional room and that is taken by the boat entitled to mark room she may not be in breach, this was the same under the old rules.
When at the Mark there is the right to sail a proper course while at the mark. There is extended exoneration here as it covers not only part A rules but also 15 and 16.
This allows for a sudden course change at the mark to sail the proper course which may be a luff at a leeward mark or a bear away at a windward mark.
Overriding all this, is the obligation of the boats under rule 14 to avoid contact, there can be no exoneration here. The rule itself though assists the boats in that a boat that is right of way or entitled to room or mark room need not act to avoid contact until it is clear that the other boat is not keeping clear or giving mark room, and shall not be panelized unless the contact causes damage or injury.
There will be other scenarios but this gives the basic idea.
Time factor?I still think there is a time factor in the concept of Room, so if a boat entitled to mark room goes too slowly and a right of way boat has to alter course, she is at risk of losing her exoneration. You have mark room but I believe you have to use it or lose it! On this point we will see.