A Flow Regatta is a field session, usually taking 6-8 hours, where new techniques and equipment is demonstrated for measuring flow in watercourses, but participants are invited bring their own equipment to take measurements. It's a social event, often with BBQ and beverages, where participants can share knowledge and techniques. We would propose a competitive component where competitors are required to submit their estimated flow (Q) and uncertainty estimate. The winners in several sub-categories would report a Q within the uncertainty bounds of the true Q. For this to be effective, knowing the true Q (preferably within 1%) is best. A flow regatta can still be run without knowing the "true" Q to see the variance of measurements, and between different techniques for a particular site and condition. We recently ran such as session using several different techniques in Lethbridge, AB, Canada. The results are written up here: http://www.fathomscientific.com/lethbridge-flo-tilla-2017/ and here:
http://aquaticinformatics.com/blog/hydrology/experience-and-stream-gauging/

We'd start the day with a 1-2 hour classroom session introducing the techniques to be demonstrated