Survey To Measure PDRacer Hulls ( the survey is closed )
Rule #1 has always said we use the same shaped hulls and at the top of the rules page it has always explained that further and shown our rocker shape for free. We have always had free download boat plans available. It became known that some duckers were intentionally modifying their rocker shapes and building outside our tolerance range thinking that they would end up with faster hulls - even though this directly violates the concept of our class. The online discussion of this issue degraded into arguments fussing over who's rocker shape is faster causing new builders to wonder what shape they should build and duckers with older hulls to think their boat was no longer competitive. All because people were intentionally violating rule #1, the rule intended to prevent this problem.
To fix the problem, we needed to reduce the tolerance range so that any variance within the range would be small enough that nobody would believe a claim their shape was faster. Next we started measuring hulls for racing so there are no questions or hard feelings later of whether a hull is class legal.
The original 1/2" tolerance was just a guess at what people needed. Below is the hull shape survey data collected between 3-31-10 and 5-24-10. It shows for class legal racing, we could use a much smaller tolerance range. I released the new 1/4" tolerance range May 24, 2010. This range is still loose enough that the average builder can easily make a hull that is class legal. Since the new range was released, careful builders have built with less than 1/8" difference from the ideal shape.
At the same time I created Rule 7 to require that non-class legal hulls be allowed to participate with a penalty. The combination of these elements allowed us to stop the fussing over different shaped hulls and get back to our original concept that we build & race the same shaped hulls. We can have serious competition with the class legal hulls out front, casual non-class legal racers with them and everyone goes home with a trophy. For more information about rule 7 see the class rules page and the rules explanation page.
A Puddle Ducker is someone who has a PDRacer hull number and there is no requirement that you must race your boat. For duckers that do not care about class legal racing, the standard has always been to simply try to build a class legal hull and go have fun with it. If you made a mistake and your hull ended up being out of tolerance, thats OK, you retain your hull number. The important part is that you honestly tried to make a class legal hull. If any time you want to race without the delayed start you can fix it or build a new hull and move your number over to it.
Michael Storer OZ Racer Sailboat Plans (not class legal)
Michael Storer sells plans called the OZ Mk-II and other soundalike names as PDRacer plans, the sales page shows a copy of our hull shape and explains a guarantee of being class legal. (Storer's site PDRacer.info here ) Customers that built them discovered the boats are not class legal and the plans use a different shape. Storer's plans are in metric, use different station marks measured from the top side and our class hull shape is specified in imperial from the bottom so it is not very obvious.
At the bottom of the chart below are dimensions from OZ Racer hulls. The first line being the dimensions that are specified in the OZRacer plans. The PDRacer has a 6" rocker and the OZRacer has a 5" rocker (after conversion from metric), as you can see the dimensions are listed in red meaning the OZ Racer Plans do not comply with our original or current tolerance range.
I prohibit sales of boat plans related to our club.
| Defined Hull Shape | 2,5 | 0,5 | 0,0 | 0,0 | 1,0 | 2,3 | 4,3 | 2,0 | ||
| OLD Range | above | 3,1 | 1,1 | 0,4 | 0,4 | 1,4 | 2,7 | 4,7 | 2,4 | |
| below | 2,1 | 0,1 | -0,4 | -0,4 | 0,4 | 1,7 | 3,7 | 1,4 | ||
| NEW range | above | 2,7 | 0,7 | 0,2 | 0,2 | 1,2 | 2,5 | 4,5 | 2,2 | |
| below | 2,3 | 0,3 | -0,2 | -0,2 | 0,6 | 2,1 | 4,1 | 1,6 | ||
| Measurements not within OLD tolerance range | ||||||||||
| Measurements not within NEW tolerance | ||||||||||
| Str Len | Shift | S1 | S2 | S3 | S4 | S5 | S6 | S7 | over bow | |
| DHS 1 | 90,4 | 0,2 | 2,4 | 0,4 | 0,0 | 0,0 | 1,0 | 2,4 | 4,5 | 2,0 |
| DHS 2 | 90,2 | 0,1 | 2,6 | 0,6 | 0,0 | 0,0 | 0,6 | 2,3 | 4,5 | 1,6 |
| DHS 3 | 90,7 | 0,3 | 2,5 | 0,5 | 0,0 | 0,0 | 1,0 | 2,3 | 4,3 | 2,0 |
| DHS 4 | 90,5 | --- | 2,5 | 0,5 | 0,0 | 0,0 | 1,0 | 2,3 | 4,4 | 2,4 |
| DHS 5 | 90,1 | 0,0 | 2,6 | 0,6 | 0,0 | 0,0 | 1,0 | 2,4 | 4,4 | 2,1 |
| DHS 6 | 90,4 | 0,2 | 2,5 | 0,5 | 0,0 | 0,1 | 1,0 | 2,2 | 4,2 | 2,0 |
| DHS 7 | 90,4 | 0,2 | 2,5 | 0,5 | 0,0 | 0,1 | 1,1 | 2,3 | 4,3 | 2,0 |
| DHS 8 | 90,1 | 0,0 | 2,6 | 0,7 | 0,1 | 0,1 | 1,2 | 2,4 | 4,5 | 1,6 |
| DHS 9 | 90,4 | 0,2 | 2,4 | 0,4 | -0,2 | -0,2 | 1,0 | 2,3 | 4,3 | 2,0 |
| DHS 10 | 90,0 | 0,0 | 2,6 | 0,7 | 0,0 | 0,0 | 0,7 | 2,3 | 4,5 | 2,0 |
| DHS 11 | 90,4 | 0,2 | 2,6 | 0,6 | 0,0 | 0,0 | 1,0 | 2,4 | 4,4 | 2,0 |
| DHS 12 | 90,4 | 0,2 | 2,5 | 0,5 | 0,0 | 0,0 | 1,0 | 2,3 | 4,3 | 2,0 |
| DHS 13 | 90,3 | 0,2 | 2,4 | 0,5 | -0,1 | 0,0 | 1,0 | 2,3 | 4,3 | 2,0 |
| DHS 14 | 90,7 | 0,3 | 2,2 | 0,4 | 0,0 | 0,0 | 0,6 | 2,0 | 4,1 | 1,7 |
| DHS 15 | 90,4 | 0,2 | 2,5 | 0,5 | 0,1 | 0,2 | 1,1 | 2,4 | 4,4 | 2,0 |
| DHS 16 | 90,2 | 0,2 | 2,6 | 0,6 | -0,2 | -0,2 | 0,8 | 2,6 | 4,2 | 2,2 |
| DHS 17 | 90,0 | --- | 2,7 | 0,6 | 0,0 | 0,2 | 1,4 | 2,7 | 4,7 | 2,0 |
| DHS 18 | 90,6 | 0,3 | 2,5 | 0,5 | 0,2 | 0,2 | 0,7 | 2,3 | 4,3 | 2,3 |
| DHS 19 | --- | --- | 2,5 | 2,5 | 0,1 | 0,2 | 1,0 | 2,3 | 4,3 | --- |
| DHS 20 | 91,4 | 0,6 | 2,3 | 0,2 | -0,4 | -0,4 | 0,5 | 2,0 | 4,2 | 2,0 |
| DHS 21 | 89,6 | 0,1 | 2,6 | 0,7 | 0,0 | 0,0 | 1,0 | 2,3 | 4,7 | 2,6 |
| DHS 22 | 90,5 | 0,2 | 2,6 | 0,7 | 0,1 | 0,3 | 1,3 | 3,0 | 5,0 | 3,0 |
| DHS 23 | 90,0 | 0,0 | 2,6 | 0,6 | 0,1 | 0,2 | 1,1 | 2,3 | 4,3 | 2,0 |
| DHS 24 | 90,0 | 0,0 | 2,5 | 0,5 | 0,0 | 0,1 | 1,0 | 2,3 | 4,4 | 2,0 |
| DHS 25 | 90,4 | 0,2 | 2,3 | 0,3 | 0,1 | 0,1 | 0,7 | 2,2 | 4,3 | 2,0 |
| DHS 26 | 90,4 | 0,2 | 2,3 | 0,3 | -0,1 | 0,1 | 0,7 | 2,2 | 4,2 | 2,1 |
| DHS 27 | 89,7 | 0,0 | 2,6 | 0,6 | 0,2 | 0,2 | 1,0 | 2,4 | 4,4 | --- |
| DHS 28 | 89,7 | 0,2 | 2,7 | 0,6 | 0,2 | 0,2 | 1,1 | 2,4 | 4,5 | --- |
| DHS 29 | 90,4 | 0,2 | 2,1 | 0,2 | -0,4 | -0,4 | 0,4 | 1,7 | 3,7 | 2,6 |
| DHS 30 | 90,4 | 0,2 | 2,2 | 0,4 | 0,0 | 0,0 | 0,7 | 2,1 | 4,1 | 2,4 |
| DHS 31 | 90,4 | 0,2 | 2,4 | 0,5 | 0,1 | 0,1 | 0,7 | 2,3 | 4,3 | 1,7 |
| DHS 32 | 90,0 | 0,0 | 2,5 | 0,4 | 0,0 | 0,1 | 1,1 | 2,3 | 4,4 | 2,0 |
| DHS 33 | 90,0 | 0,0 | 2,5 | 0,4 | 0,0 | 0,1 | 1,1 | 2,3 | 4,4 | 2,0 |
| DHS 34 | --- | --- | 3,0 | 0,7 | 0,0 | 0,0 | 1,0 | 2,5 | 4,3 | 2,5 |
| DHS 35 | 90,2 | 0,1 | 2,6 | 0,6 | 0,1 | 0,1 | 1,1 | 2,3 | 4,4 | 1,6 |
| DHS 36 | 90,6 | 0,2 | 2,6 | 0,3 | 0,0 | 0,0 | 1,0 | 2,4 | 4,5 | 2,1 |
| DHS 37 | 90,6 | 0,2 | 2,4 | 0,3 | 0,0 | 0,0 | 1,0 | 2,3 | 4,3 | 2,2 |
| DHS 38 | 90,5 | 0,3 | 2,5 | 0,5 | -0,1 | -0,1 | 1,0 | 2,4 | 4,5 | 1,7 |
| Dimensions from OZ plans | 3,3 | 1,4 | 1,0 | 1,0 | 1,6 | 3,1 | 5,0 | 1,5 | ||
| OZ2 1 | 90,3 | 0,2 | 3,1 | 1,3 | 0,6 | 0,7 | 1,5 | 3,0 | 4,7 | 2,2 |
| OZ2 2 | 90,4 | 0,2 | 3,2 | 1,4 | 0,7 | 0,7 | 1,5 | 3,1 | 4,7 | 1,4 |
| OZ2 3 | 90,2 | 0,1 | 3,0 | 1,2 | 0,5 | 0,5 | 1,3 | 2,7 | 4,6 | 1,4 |
| OZ2 4 | 90,3 | 0,1 | 2,7 | 1,1 | 0,4 | 0,5 | 1,3 | 2,7 | 4,6 | 1,4 |
| OZ2 5 | 90,1 | --- | 3,1 | 1,2 | 0,6 | 0,7 | 1,4 | 3,0 | 4,6 | 1,5 |
| OZ2 6 | 90,4 | 0,2 | 3,2 | 1,4 | 0,6 | 0,6 | 1,5 | 3,0 | 4,5 | 1,4 |
| OZ2 7 | 90,3 | 0,2 | 3,1 | 1,3 | 0,6 | 0,7 | 1,5 | 3,0 | 4,7 | 2,2 |
| OZ2 8 | 90,4 | 0,2 | 3,0 | 1,4 | 0,7 | 1,0 | 1,6 | 2,2 | 5,0 | --- |
| OZ2 9 | 90,4 | 0,2 | 3,0 | 1,3 | 0,6 | 0,7 | 1,5 | 2,1 | 5,0 | --- |
Source Of The Data
Some of the duckers that submitted data were just casual builders and did not race, some others were precise builders and hard core racers meaning this data is a good variety that represents different types of duckers.
The data in the table are the actual measurements submitted from duckers. When I received the data I compared the email address with their membership listing to confirm it was submitted from our members. I list just the measurement data in the table. Upon completing the survey to protect the privacy of our members, I deleted all the source emails and flushed my cache so it is not possible to track backwards to see who submitted which set of data.
Hindsight About Measuring Hulls
The string line measuring system and tolerance range has been with the club since the beginning, but we had no penalty. This was naive on my part, I thought everyone would simply be honest and follow the rules. With the experience of having to resolve this problem I can now see the importance of having a soft penalty for breaking our rules.
It is about the same as speeding tickets. When driving down the road 95% of the people will follow the speed limit because that is what is asked of them. Unfortunately there is about 5% which will blatantly ignore the speed limit especially if there is no way to give them a speeding ticket.
When the few were caught they made a fuss in various online forums starting all sorts of confusing arguments to conceal they were caught cheating. They were joined by a few trolls who look for any sort of controversy to fuss about. With online forums just a couple of people can make a small issue seem like a huge one.
We now measure hulls for racing and like speeding tickets, we have a soft penalty for violating our class rules as stipulated in rule 7. The most important part is this motivates the 5% to go ahead and follow our few rules like the rest of us. Our tolerance range is still very big and the penalty is only a soft annoyance, not like your boat is going to get confiscated. The hull shape cheating is the only real problem we have experienced and I hope this delayed start penalty can fix it so we can get back to our original concept without further problems. Time will tell if this is will fix the problem or we need to make more adjustments.