Sailboat Handicapping Systems

PHRF is not fair, IMS is too expensive, Americap doesn't have a big enough database, ORC Club is an unknown, so let's do our own system…Grand River Handicapping (GRH).

Calculation of Distance Sailed on a Beat or Run

Geometric Proof of Distance Sailed on a Beat or Run (Easier to Understand)

PHRF, IMS, and Americap: A Comparison of the Handicapping Systems, by PGMathews

This three year old paper gets about 10 hits per day!

Comments on the PHRF, IMS, and Americap: A Comparison of the Handicapping Systems

Letter from Sir Peter Johnson

Some comments via email

Mathematics of Americap, by PGMathews

Scientific Notebook Viewer is needed

http://www.mackichan.com/snbk/download/orderblk.htm

or view as jpg pages

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Proposed Grand River Handicapping System

Repairing chainplates on a J/35

I just completed a repair to Whitehawk that I thought I'd share. We've had three boats now that have had balsa cored decks. All three have had chainplates that attached to bulkheads through the deck, and all three have had wet core around the chainplates. Unless you have a recently built Tartan you probably have the same problem. Now on Scars and Scrapes (our J30) and Whitehawk the builder doesn't do anything special about sealing the deck at the chainplates because the bulkheads take all of the load and are built from solid fiberglass. This is not the case on many boats. If you've got a plywood bulkhead and wet core in the deck your bulkhead has probably been compromised. This spring on Whitehawk I cut a 5"x3.5" rectangular chunk of deck out around the chainplates. I made the cuts through the top skin of the deck and used a 1" holesaw to radius the corners and a keyhole saw to connect the holes. The lower skin was left intact. I was surprised that the balsa directly under the cuts was dry (yeah!) but most of the core near the chainplates was like oatmeal. I scraped out all of the core and then mounted fake chainplates that I made from pine. I marked and cut the pine so it was flush with the upper deck and then waxed the top and sides of the pine. I used some putty epoxy to seal the pine to the lower deck skin and then used fiberglass and epoxy to fill the hole. I built up the glass in three lay-ups and brought it to within 1mm of the top of the deck. I filled the last 1mm with West epoxy with some filler to thicken it and some white pigment to provide a base for the finish gelcoat. Then I sprayed white gelcoat (thinned 20% with acetone) over the repair. After some sanding the repair looks pretty good. Maybe not quite as good as the factory would have done, but now my deck around the chainplates is solid glass and theirs isn't! I sealed the chainplates at the deck with BoatLife Seal caulk. That's one repair I'll never have to do again!

Tips for New Crew

Sailboat Racing Primer for New Crew and Skippers at GRSC, 1 page boat trim guide, jib trim-what good & bad sail tics look like

J/35 Reference Material (This is a list.) The following J/35 reference material is being posted for the varsity sailing team of the US Naval Academy. Good luck racing your two J/35s! Caution: Some of the optical character recognition scanned documents still contain errors! To save space I made the images smaller. To regain size and image clarity download the images from http://junior.apk.net/~pmathews/j35 Then use a image editor and edit the pictures by doubling them in size and use the "sharpen" feature.

OLD North Sails J35 Tuning Guide with 4 pages of Keelboat champion Andreas Josenhans shares his high-speed techniques and rigging details for the J/35 page1 page 2 page 3 page 4

NEW North Sails J35 Tuning Guide (This pdf file is 1 Mbyte but worth the download time. This file was provided by North Sails and I have permission to post this to the web.)

The Role of the Tactician (on a J/35) by Bear Hovey

Getting Back To Basics: Crew Organization for Spinnaker Hoists, Jibes and Douses by Ron LaNeve (on a J/35)

Portions of J/35 Owner's Manual, Rigging, Sail Controls and Tuning

J/35 Basic Specifications, Tuning Summary and Polars

List of Marinas, Businesses & Organizations on the Grand River

Our St. Martin 2002 Cruise