DO NOT recommend the Suunto M9. Neat idea, seldom works, lots of head-down button pushing at critical times when you can't afford it. If it does turn on the GPS and it does have a signal and your battery doesn't expire (life is about 1 1/2 hr) and the delay is not too great (several second speed change lag compared to a fixed Garmin), it is neat to see SOG on your wrist. I recommend any portable unit on a lanyard around your neck or in a clear pouch on your clothing over the M9. I mounted a Garmin 176 on my front beam and it worked great with either a chart view or huge and legible numbers.