Scenario #1 - Deeper Dive

Scenario/Quiz #1 - A Deeper Dive

After a great discussion at Seminar #2 regarding Quiz #1 (where it's possible that neither boat is the right-of-way boat) I've put together a few diagrams that expand on this "hole in the rules".  In the end, the "hole" is usually short lived in "normal" scenarios, but for the "sailing by the lee" scenario, it can exist for the most of the interaction.  In either case this is quite unexpected for most people!

I recommend reading the Quiz #1 Answer first before continuing here.  I also suggest you have a rule book handy as this explanation relies on the exact wording of rules and definitions, and won't likely match common intuition.  

Case 1:  Neither boat has the right-way (equally neither boat must keep clear)

In the scenario to the right, I show 5 downwind possibilities for the Blue boat while the Yellow boat (the same for all Blue possibilities) is on a close hauled course (assume only one Blue at a time when interpreting this). I've drawn a red line along the centerline of each boat to help make it clear that the port side of this red line is always the leeward side of the boat.

• Yellow and all the Blue variations are on starboard tack (even the "by the lee" Blue boats)
• The left two Blue boats are sailing "by the lee" (not particularly material to the discussion, but highlights the definition of leeward and windward).
• In every case Blue and Yellow are overlapped (read the definition of overlap if this isn't clear).
• By the strict definition of windward/leeward boat, none of the boats have a boat to leeward of them
• Thus, according to the definition of windward/leeward, none of the boats are windward boats (this is CERTAINLY non-intuitive and a quirk of how the definition is written)
• Rule 11 states that the "windward boat shall keep clear", which is neither Yellow or Blue, so NO BOAT must to keep clear of the other (under Rule 11 at least)
• Only Rule 14 (Avoiding Contact), continues to apply.

What should strike you as surprising is that at least the right 4 possibilities for Blue are not at all uncommon (the leftmost Blue boat is significantly by the lee.  Not something displacement boats do that often, but Lasers and other dinghies certainly do).  Picture a windward mark where some boats have rounded and are heading downwind (Blue) and others are still sailing to windward towards the mark (Yellow).  I've been in this situation a hundred times if not more.   

• The relative position of these boats is very important, and
• When put in motion, which boat is windward boat or leeward boat or neither, may change as the boats progress through the water.
• For most of these examples, there is a low probably of actual contact, but it is certainly a possibility.

Case 1: In Motion (Dead Downwind)

This scenario is really only putting "motion" to the "dead downwind" Blue boat from first diagram (above) and the Yellow boat.  Postion 2 in this diagram is what is represented above.  This scenario also shows the "just before" (Position 1) and the "just after" (Position 3).  Analyzing this with the boats in motion exposes the fact that this "hole in the rules" is short lived but not without the possibility of contact and thus a certain amount of risk.

Position 1:

• Blue and Yellow are both on starboard tack and both are overlapped
• Yellow is to leeward of Blue
• Therefore Blue is the windward boat and must keep clear (Rule 11)
• RISK: Contact is certainly possible (but Yellow looks to be able to pass in front of Blue and we would expect Blue to keep clear when they get close)

Position 2:

• Blue and Yellow are still both on starboard tack and both are still overlapped
• Yellow is NO LONGER to leeward of Blue (this just changed from the previous position)
• Blue is NOT to leeward of Yellow
• Therefore NEITHER is the windward boat and NEITHER must keep clear
• Only Rule 14 applies.
• RISK: There IS still a possibility of Blue's starboard side making contact with Yellow's starboard transom. 

Position 3:

• Blue and Yellow are still on starboard tack
• Blue and Yellow are NO LONGER overlapped
• Therefore Rule 12 (Same Tack, Not Overlapped) applies
• Blue and Yellow are clear astern of each other (mmm ... read Rule 12)
• But neither Blue or Yellow are clear ahead so neither must keep clear at this point! (yet another situation where none of the primary Section A rules apply (except 14)
• RISK: They are now past each other with no possibility of contact, so the fact that Rule 12 doesn't tell us who should keep clear is somewhat moot.

Key Take Aways:   

• In this not an uncommon crossing situation there is a "moment" (about a boat length or so) when Yellow loses their right-of-way at the very moment of possible contact and during that "moment" BOTH must do what they can to avoid contact (Rule 14).   
• Since this "hole" is momentary, and most sailors wont be aware of it and both Blue and Yellow are likely to carry on thinking (and behaving) that Blue remained the keep clear boat until they have passed each other.
• Strictly speaking, at Position 2, BOTH Blue and Yellow should have taken some avoiding action (assuming the possibility of contact).  If there WAS contact, a jury would look to the boat that took no avoiding action for a possible DSQ!  Neither boat could be exonerated by 43.1(c), because neither are the right of way boat.
• Again, a surprising result and not what your intuition will tell you.

Case 2: In Motion (Sailing by the Lee Downwind)

This scenario is really only putting "motion" to the original Quiz #1 question where the Blue boat is sailing "by the lee" on a parallel course (180 degrees different) from above and the Yellow boat is sailing upwind close hauled (also the leftmost Blue boat in the diagram at the top of the page).  Postion 2 in this diagram is what is represented in the original Quiz #1. This scenario includes the "just before" (Position 1) and the "just after" (Position 3).  Analyzing this with the boats in motion exposes the fact that this "hole" can be more than short lived.  There is definitely the possibility of contact.

Position 1:

• Blue and Yellow are both on starboard tack and both are overlapped
• Neither boat is to leeward of the other, and thus, but the strict reading of the definition of windward and leeward, neither boat is to windward of the other
• Therefore neither boat must keep clear (Rule 11)!

Position 2 (same as Position 1):

• Blue and Yellow are both on starboard tack and both are overlapped
• Neither boat is to leeward of the other, and thus, but the strict reading of the definition of windward and leeward, neither boat is to windward of the other
• Therefore neither boat must keep clear (Rule 11)!

Position 3:

• Blue and Yellow are still on starboard tack
• Blue and Yellow are NO LONGER overlapped
• Therefore Rule 12 (Same Tack, Not Overlapped) applies
• Blue and Yellow are clear astern of each other (good, but... read Rule 12)
• But neither Blue or Yellow are clear ahead so neither must keep clear at this point! (yet another situation where none of the primary Section A rules apply (except 14))
• RISK: They are now past each other with no possibility of contact, so the fact that Rule 12 doesn't tell us who should keep clear is moot.

Key Take Aways:   

• While this is less common for keel boats (not so for Lasers, etc.), it's still possible and the "hole in the rules" exists until they leave each other clear astern.  
• Strictly speaking, at Position 1 & 2, BOTH Blue and Yellow should have taken some avoiding action (assuming the possibility of contact).  If there WAS contact, a jury would look to the boat that took no avoiding action for a possible DSQ! Neither boat could be exonerated by 43.1(c), because neither are the right of way boat.
• Again, a surprising result and not what your intuition will tell you.