Yellow and Green are well below the layline within the zone, but it is not clear whether RRS 18 applies.

On the one hand, it is not clear that the boats are "about to round or pass" the mark, for two reasons:

• They must both do two tacks before they could correctly pass the mark.
• Neither boat has the mark on the required side.

On the other hand,

• ISAF case 84 gives us a strong hint that boats in the zone are almost always about to round or pass.
• As of writing (September 2004), the RRS for 2005-2008 is likely to say that RRS 18 applies when boats are about to round or pass or when they are in the zone, whichever occurs earlier.

Even if RRS 18 applies, it is not easy to say which boat enjoys the room granted to it by 18.2(a).  The boats are certainly overlapped, but 18.2(a) only gives rights to room to the 'inside' boat, and it isn't clear which of these two boats is 'inside'.  ISAF case 2 helps us a little, because it says that "When rules 18.2(a), 18.2(b) and 18.2(c) do not apply, right of way is determined by the relevant rule in Section A of Part 2".  At entry into the zone, both Green and Yellow are about equidistant from the mark, though when we get a little further into the sequence, Yellow comes closer to the mark than Green.

Let us imagine that Green starts to luff in an attempt to get Yellow to tack to port.

 Remind me:

Before clicking on a letter to see what we think, decide for yourself if you think the statements are true or false...

Assuming RRS 18 does NOT apply:

 Green had passed head to wind when contact occurred, so she broke RRS 13 by not keeping clear of Yellow. Yellow failed to respond to Green's luff, so she broke RRS 11 by not keeping clear. Yellow should have anticipated that Green would want to tack. Green was too close to Yellow to start luffing. Green had no luffing rights at all.

Assuming RRS 18 DOES apply, and that Yellow is the inside boat:

 Green had passed head to wind when contact occurred, so she broke RRS 13 by not keeping clear of Yellow. Yellow failed to respond to Green's luff, so she broke RRS 11 by not keeping clear. Yellow can sail Green off the mark before tacking.

Let's have a look at the next page to see what might happen if Yellow sails Green off the mark.

2018-06-23