3 Lengths; Overall, Boat or Hull?

I received a mail from Greg who writes about the the wording in the definition of Zone and how sailors interpret those:

 

Hello

I enjoy using your blog to help clarify my own understanding of RRS.

Here is a local issue in my area that might be worth a post & response. This is not an issue from the elite levels, but I think a concern in recreational racing fleets. This is another area where careful wording in the rules needs to become careful wording in discussions, so sailors are not inadvertently lead astray.

Whether it was the previous rule, or the current definition of Zone, we continue to informally refer to the distance as boat lengths rather than hull lengths (as defined in RRS). This has caused some interesting confusion among local competitors in boats such as International 14s, which in the past used the informal wording of "boat" to define their distance from the mark. The sailors included both the hull and the extended bowsprit multiplied by 2 to determine the "circle" heading into a mark where the bowsprit was deployed.

When they were reminded in discussions of rule changes that RRS 2009 defines Zone as 3 "Hull" lengths, they responded that the 2009 revision would effectively decrease the size of the Zone compared to their past practice.

From http://gallery.me.com/npatchett#100014

Is this an issue in other localities? Shouldn't we quit talking about boat lengths and say or write hull lengths when we talk about the Zone. From my perspective, using the term "hull length" consistently would help clarify the situation for competitors.

Greg

 

Hi Greg, thanks for you input!

You are absolutely right in referring to the zone in Hull-lengths always!

I know there are several rules which have to do with measurement or the position of boats, their equipment and the place it is normally used in (at starting, finishing or to determine the zone). But for the zone, the circle should be fixed for all boats in the same class.

The international 14, who has a retractable bowsprit, would otherwise have a different zone depending on how far the bowsprit is extended. The rule makers wanted to avoid any misunderstanding in that regard and (I suspect) deliberately chose to use hull length. You can find those in the class rules drawings and it should be fixed within a small tolerance. That tolerance should – at most –produce a difference in the zone of a couple of centimeters, not enough to make any difference on the water.

In some older rule books the zone was defined by two boat lengths or two overall boat lengths. Without a variable “length” – like with the bow sprit of the more modern 14 – that was also a fixed measurement. Carbon materials were not available generally and even the most seasoned hickory would have split in those dimensions. (Hickory is a wood used for hammers and axes – because of it’s tensile strength) To my knowledge, they did not have retractable bowsprits in those days… I’m talking about 80’s…

If in the previous rule cycle, sailors used to measure the zone with an extended bowsprit, they did not use the correct definition and that can lead to misunderstanding.

If the sailors in International 14 class feel that three hull-lengths is not enough to prepare for rounding a mark, they have the possibility to increase the zone to four hull lengths, provided it is clearly stated in the SI. Talk to the club and / or RO. I bet they are willing to provide amended SI’s to that effect. With four hull lengths the zone should come to a little bigger then two with an extended bowsprit – if I judge the dimensions correctly from the photo’s

Greg is also asking for responses from other local sailors. Please leave a comment if you have something to contribute.

J.