Thanks for reply was just wondering if I could go faster on the Go will try and keep you posted. The 49km was with a 9.0m 2011 Freerace sail of Simmer. Some sailors are using a Go and log their result at gps.speedsurfing.com, but I understand it is not a board when you are interested in speed. I bought the complete set also for my kids with a small sail 2.5m, now I am looking for the SB Ultrasonic 147 and a RRD FireRace 122 to make the set complete.
Keep you posted if I manage to put 55km on the clock.