Can only recommend the GW60, really heavy duty and it has exactly what is needed, and not TOO big like many are.
With the new SW release a month ago the missing options we also would love, has been added - and it is spot on MADE for speed of course with the max speed and 1 second and 2 second and 500 m and so on, speeds that you can see without pushing any buttons when set up for you, but assume everybody knows this from gps-speedsurfing.com where the kite and windsurf "speed riders" has developed and told the software guys at locosys exactly what is needed, this is one of the best teamworks I've seen, awesome
The GT-31 was perfect in this respect too, but old fashioned so not in a modern wrist watch design, so great to see something that just works - using mine every session out both waveriding and hydrofoiling, maybe just as a normal watch sometimes
PF