As I believe my swim between Oroville WA, USA and Osoyoos BC, Canada on Osoyoos Lake to be a first attempt I wanted to get as much data as possible. English Channel relay swimmer Phred Martin was asked to act as swim observer and took notes as we progressed north to Canada. Two digital thermometers were mounted in the front of his kayak, one to measure water temperature and one to measure air temperature. The final swim distance and track was taken from the FINIS Hydro Tracker GPS that was mounted on the back of my head attached to my goggle straps.
Link to .pdf of swim report here(full screen): http://www.nothinggreatiseasy.com/wp-content/uploads/2014/09/Swim-report-for-Oroville-to-Osoyoos-swim.-Swim-date-Sept-6th-2014..pdf