So then how do you figure for a staggered start where everyone's start time is adjusted based on pHRF so that in theory they finish at the same time? According to the calculation above you would still need to adjust for the total elapsed time. Also is the elapsed time the 1st finishing boat (fastest) or your boat using your rating?

With a normal start, each boat’s corrected time uses their own elapsed time in the formula.

To give an example (with simple numbers for easy math) - if you have a 2 mile course, you finish in 30 minutes, and your competitor with a 100 PHRF finishes in 25 minutes:

Your elapsed time is (30 minutes * 60 seconds per minute) = 1800 seconds.

Your corrected time is 1800 seconds - (289 * 2) = 1222 seconds.

His elapsed time is (25 minutes * 60 seconds per minute) = 1500 seconds

His corrected time is 1500 - (100 * 2) = 1300 seconds.

Your corrected time is less than his, so you win.

For staggered starts (pursuit style) you kind of need to work backwards to pre-calculate start times based on handicaps and course length.

Basically you have the highest PHRF boat start first, then each next slower boat starts later by the difference between their PHRF and the next faster boat, times the course length. Then whoever finishes first wins outright.

So for an example of that, say you have a 2 mile course, and 3 boats rating 289, 100, and 90. The 289 will start at the first start time, say 10:00:00. The 100 PHRF boat owes him (289-100)*2 seconds, which is 378 seconds, so they’ll start 378 seconds after 10:00:00. The 90 PHRF will start (289-90)*2 seconds after the 289 boat, which is 398 seconds after 10:00:00. All of the handicap is therefore pre-calculated, so whoever crosses the finish line first wins.