How do PHRF ratings work?
In PHRF, boats are assigned ratings in seconds per mile. Your rating is the number of seconds per mile your boat is supposedly slower than a theoretical boat which rates 0. Most boats you are likely to sail on rate somewhere in the range of about 50 to 250.
What is sailboat comfort ratio?
Motion Comfort Ratio was developed by Boat Designer Ted Brewer. The formula predicts the speed of the upward and downward motion of the boat as it encounters waves and swells. The faster the motion the more uncomfortable the passengers. Thus, the formula predicts the overall comfort of a boat when it is underway.
How do you read a polar sailboat diagram?
Polar plots are published by each manufacturer for each model of boat with their various sail plans. It’s easy to read – move your finger radially along any true wind angle. Stop when you reach the boat performance line associated with the true wind speed you are experiencing.
What is a blue water sailboat?
A blue water sailboat is a boat that is designed for extended voyages in open water. The opposite are inland production boats.
What is Polar speed adjustment?
The polar speed adjustment is a percentage adjustment on your set base polars. Having it set at 100% reflects your set base polars, however you may wish to adjust these polars. For example setting the polar speed adjustment to 90% will take 10% off your set polar speeds for your next weather routing download.
How do you calculate ballast displacement?
The formula for this calculation is (D-f)LWL x B, where D = molded depth, f = freeboard, LWL = vessel length at waterline and B = beam of the vessel. Divide the amount of ballast to be added or removed by 64.1.
What is a capsize ratio?
Capsize ratio indicates the likelihood that a boat will recover from an inverted, capsized position. It was developed during tank tests conducted after the Fastnet race disaster.
What does PHRF stand for in sailing?
Performance Handicap Racing Fleet
Performance Handicap Racing Fleet (PHRF) United States Sailing Association sanctions regional authorities to administer the national rule and develop regional by-laws.
What is IRC in yacht racing?
IRC Rating IRC is a true rating system, where the yacht’s handicap, expressed as a time correction factor (TCC), is derived solely from the yacht’s measurements and characteristics and is not arbitrarily modified according to the yacht’s perceived performance.