GBCA Discussion Forum

Mark
You noted previously "The interest shown by the sailors on the Forum is great. I hope that I can clarify on item - measurements. More specifically the freeboard measurement that determines the boat displacement. This is not required - but it is in the best of the boat to have the freeboards measured. If not measured - the boat will receive the lightest weight in the database for that class."

Can you tell us more about how to get the freeboard measured?  Is there someone in Galveston Bay who can do this?  I looked at the details and this measurement does not appear simple.  Please clarify
Dave Christensen
S/V Airborne

If you own a J/Boat please join us for a weekend of racing on Galveston Bay hosted by Lakewood Yacht Club.  The weather at the end of October is some of the best of year; warm water, cool temperatures and plenty of wind. Early sign up's get regatta tech shirts for the entire crew!   Saturday night will feature J/Fest's traditional Frogmore Stew (Shrimp, Shrimp.... and more Shrimp) with entertainment by the LC Roots Band.

Check out the new J/Fest web site and register at http://www.jfestsouthwest.com/, looking forward to a great turnout this year !

J/ Fest Southwest will take place on Galveston Bay Oct 29, 30th.   If you own a J/Boat but cannot sail the event please consider chartering your boat to a qualified skipper and crew.  We have out of town crews that want to charter a local J/Boat.

Please let me know by email. 

Dave Christensen
dc1sail@comcast.net

Please join us on Saturday July 30th for the third seminar in GBCA's Learn to Race Series: Strategy & Tactics

Strategy – how to sail the course fastest in the absence of other boats
   Wind Conditions: oscillating, persistent & mixed wind conditions
   Sources of Weather information
   Upwind & Downwind Strategy in different wind conditions
   Typical Weather systems in Galveston Bay:  Cold Front,  Sea Breeze, impact on strategy
   Rum  & Icicle Race – Issues unique to these races

Tactics- what to do when encountering another boat
   Upwind, tack or duck?
   Bad Air – consequences
   Should I go to the lay line?
   Controlling another boat
   Consolidate your gains
   Covering a competitor

This is the third and final part in a series of events designed to introduce sailors to all the conditions that could affect your decisions. 
The Seminar starts at 9:00 am.  Check in starts at 8:30 am. Seminar will be over by 2 pm.  Lunch and soft drinks/water will served. All of this for only $20.00!!

JD, there is no requirement to have the boat measured for a club certificate (suitable for racing in Galveston Bay).  However, if you want an international certificate  you must get the boat measured by a certified ORC measurer. Currently there is no such person in the area that I know of.  You would need to fly in Dobbs Davis (ORC representative in the US) or someone like him to do the work.   You only need an international certificate to do the big stuff like the ORC worlds. Key West Race Week used the club approach last year.  Suggest you look the J/122's currently in the ORC database.  I will bet there are some that have international certificates.  It is best to go start with a boat that was measured since the data will be more accurate.  Pick one that is set up like your boat and copy it.  Then change what ever data you need to change (typically sail dimensions, sail inventory, crew weight) and save it as your boat.  You then get a test certificate and can run off the polar diagrams and target boat speed numbers.  The test certificate has everything that the final certificate has but it is not valid for racing since it has not been submitted/ paid for or checked by ORC.  Once you are happy with the test certificate then submit it to get the club certificate.  If you need assistance let me know via email.  I am happy to help.
Dave Christensen
S/V Airborne

GBCA's seminar series continues Saturday July 16th with a class on sail trim.  This is the second part in a series of events designed to introduce new or inexperienced skippers & crew on how to make a boat go faster. The seminar will finish in time for sailors to get to their boats so they can participate in Rum Race. #3. 

The course covers:

Theory, the Language of Sail Shape
Main Sail Trim , controls and settings
Genoa / Jib Trim, controls and settings
Symmetrical Spinnaker Trim, controls and settings
Asymmetrical Spinnaker Trim, controls and settings

Cheat Sheets for each sail / wind condition (suitable for lamination & cockpit use) will be provided

The Seminar starts at 9:00 am.  Check in starts at 8:30 am. The seminar will be over by 2pm. Lunch and soft drinks/water will served. All of this for only $20.00!!
If you are new to Sail Trim or want to improve your knowledge of this subject please attend !

Everyone who races in Galveston Bay has an interest in promoting fair ratings.  It is frustrating to race often knowing that the conditions that day favor one boat type over another and that your effort is probably not going to result in getting on the podium.  While PHRF is a great system due to its simplicity and low cost it is not perfect.  The system is empirical and set up to handle only one type of course and one wind condition.  Anytime those conditions are not met the PHRF ratings often do not reflect the performance of many boats.  The other approach is a science based system using a boat's measurements (weight, waterline, draft, rig, sail area, etc....) to develop a math model that predicts the boat's performance over the full range of wind strengths and wind angles.  Typically called Velocity Prediction Programs (VPP), these models allow a naval architect/ boat designer to try out many concepts and fine tune a design before it is built.  They also allow different speed ratings to be established for a given boat depending on wind strength, type of course, etc.....the rating of a typical boat will be different sailing windward / leeward's vs a point to point course.  Since a boat will have multiple ratings for different types of racing/ courses these measurement based rules allow the race committee to fine tune which rating will be used for a given race or regatta to better match ratings with conditions / courses.   So...in theory these type of rules could lead to fairer racing.

While these VPP based solutions are not perfect, the higher end of our sport has evolved to using science based rating systems in major regattas word wide.  US Sailing, the governing body of our sport in the US, has established a relationship with one of the major science based rating systems, the ORC (Offshore Rating Congress).  The ORC sprang from the old IOR and IMS systems and has been refined over decades.  ORC now has a "Club" rating where boats do NOT have to be pulled out of the water & measured.  Data about the boat is simply entered into the database and the rating certificate is issued.  Often you can pull up a certificate from a sister boat and copy the data over to your boat and then make any changes to reflect your sails, etc....  The certificate cost is approx. $100.  The data comes from boats already in the ORC database (over 90,000 boats so far) or from the builder / designer.   Many types of production cruising boats are in the database, S2's, Cal's, Beneteau' s, Ericson's, etc.....

Over the last few months there have been a number of meetings sponsored by PHRF Galveston Bay to discuss whether adopting the ORC (Offshore Racing Congress) rating system would be of interest to the sailboat racing community.   The GBCA Board of Governors has been asked to consider supporting the adoption of ORC for GBCA events.   After extensive discussion, the BOG is willing to support ORC provided a sufficient number boat owners obtain ORC rating certificates to make the effort worthwhile.   The club will have to obtain special software, learn how to properly apply the system based on conditions & courses , etc....

A guide book that explains this in more detail can be found at http://www.orc.org/rules/ORC%20Guidebook%202016.pdf.  You can see if your boat is in the ORC database by going to http://www.orc.org/index.asp?id=1


Discussion invited.......

Dave Christensen
Member, GBCA BOG
s/v Airborne

If you are new to sailboat racing, or just interested in finding out the basics from both the skipper's and crew perspective, please join us on Saturday 4 June at 9 am in the GBCA clubhouse.  You can sign up on the GBCA web site.  The seminar includes lunch and covers:

·         Boat & Skipper Preparation
·         Building a crew.... from the skipper's perspective
·         So you want to crew.....how to get involved --- and be   invited back!
·         Offshore Sailing / Racing – it is different !
·         Which races to enter, what class fits your boat and skill level, obtaining a PHRF certificate
·         Rules for each stage of the race – the essentials only

Check in starts at 8:30 am. Seminar will end around 2 pm to allow sailors to get to boats. Lunch and soft drinks/water will served. All of this for only $20.00!!

The ORC is indeed based on a sophisticated Velocity Prediction Program (VPP) which is continually being updated.   

Quoting from the ORC web site:
   
As a result of having the complete matrix of predicted boat speed at various wind strengths and directions, ORC rating systems can therefore provide a variety of methods to calculate corrected time.

Scoring options offered include the most sophisticated, where the boat's performance is taken in consideration depending on the wind conditions, but also simple scoring options using single number scoring coefficients in either Time on Time or Time 0n Distance formats. Simple scoring options also include Performance line as a combination of Time on Time (ToT) and Time on Distance (ToD). There is also the Triple number system that uses three different Time on Time coefficients to be used in light, medium and heavy breezes. All simple scoring options are also given for either Inshore (windward-leeward) or Offshore races.
This wide variety of scoring options may look complex, but it is actually one of the strength of the ORC rating systems to offer race managers a variety to choose from that best suits their fleet, their race type and their race conditions.

The factors race managers should consider when choosing which scoring type to use include:
•   type and level of the fleet - better to use simple systems for club-level racing
•   type of race- windward/leeward or an offshore race
•   the difference between fastest and slowest boat - important to know how to divide classes and to combine entries for overall prizes
•   prevailing weather condition- are they steady or variable during the race
•   tradition of particular type for eg, Time on Time or Time on Distance
•   is there current in the area, and can it be predicted - if not, then ToT is better than ToD

Because the ORC VPP can predict the performance potential of different boat types, it can rate them fairly against each other in any range of wind conditions and course types. In this way Performance Curve Scoring can make handicap yacht scoring significantly more fair than any single number scoring approach.


The ORC database contains over 70,000 boats.  Many production boats are included such as S2's, Melges, J Boats, etc.....it is easy and inexpensive to create a certificate, just copy the data for an existing boat of your type and then make any changes to reflect your sail inventory, rig or crew weight. You typically do not have to get boat measured unless you modified it.  I created a test ORC certificate for my J/109 just to get the polar curves - the ORC VPP can handle code zero's and reaching kites and gives the cross over points between jibs, CO and running kites for each wind speed.  We have found the VPP Target boat speeds/ angles very accurate except for deep running.

If you find a single point rating system frustrating for handicap racing then you might find the ORC presentation interesting.  Will it solve all the handicap problems - I doubt it !! ...... but it might make handicap racing a bit more fair?   A big question is how the various race committee's will deal with this.  It may add to their work load?

Dave Christensen
S/V Airborne

Many Thanks To Andy Westcoat, skipper of Harm's Way,  for the great food he provided after Rum Race #5.   The brats were excellent and the potato salad was simply to die for ! 

Dave Christensen
S/V Airborne

Many thanks to the Race Committee and all the GBCA volunteers who made this such a fun event !  I loved that guitar player !
Dave Christensen
S/C Airborne

I wonder why only two J 105's signed up for the HOOD???
Dave
S/V Airborne

Quote from: beverly on September 18, 2012, 10:37:07 PM
I guess Denise beat me again....she's signed up just ahead of Shaken Not Stirred.  She's helming again, right Dave?   

Beverly, Denise will be giving you a break as I will be helming Airborne.....

Bee, I used the Kattack for last Sat's Rum Race (#6),  just logged onto J105 Fleet 17.  The entire boat track was overlaid on a chart of Upper Gal. Bay when we finished .

VERY COOL, thanks for getting this going
Dave

Bee, I have the Kattack App on my I phone (finally), are you going to try this for Rum Race #6 Tomorrow?
Dave Christensen
S/V Airborne