Thanks to the Carnac report. Sounds like you had fun. I was so bold to take your GPS Track and analysed it. I guess your device is a Garmin etrex or similar device from Garmin, which makes some rounding error. Your best speed for 10 second was 16.3kts +-0.8kts. Sounds less spectacular then 21, but is still fast. For example, the best 10sec speed on a T, we loged so far, was 18kts.
