You sail a submarine ... or have a nuclear reactor ??? Wow, I'd figure that you'd get more than 7 seconds for hauling around so much lead.
Anyhow, PHRF is a linear formula that does not do well for great differences in speed or hull types - you cannot compare James' 40-knot submarine with my slow cruising boat, no matter how many seconds a mile he must give me. Also, it errs on the side of simplicity because it is based on seconds-per-mile (time over distance), rather than seconds-per-hour raced (time over time). This means the rating assumes "normal" race conditions with plenty of wind. When you have a particularly slow race (light air or heavier seas), a normal half-hour three-mile race may double in time, but the handicap does not change (still three miles times the difference in boats). As noted, that's much easier to calculate than multiplying by each boat's elapsed time.[/QUOTE]
There are a lot of shortcomings with a Time on Distance handicap, i.e., seconds/mile. The most obvious is that it is difficult to accurately measure distance on the water. Sure the weather mark was dropped at 1 mile from start line, but is it still 1 mile after it sets and the RC squares the line? As Parson notes, for TOD to work, the conditions must be constant throughout the race, which they seldom are. In a dying breeze faster boats get a bigger advantage.
A better method is to convert the TOD handicaps (102, 114, etc) to Time on Time handicaps. First time can be measured more accurately than distance, and varying conditions become less of an issue because only time is being measured and not time and distance. Here's a link to an article on TOT: www.phrf-lo.org/images/Documents/Time_On_Time_Scoring.pdf
