I recently got myself a Garmin Forerunner 255 (for approx. 250 USD), finally managed to instal GPSTC V4 on it and I hope to give it try on the water tomorrow.
Not sure I really want to use all these gadgets and "smart" features that are offered, heart rate health and sleeping habits etc. The watch just told me the following: "The duration of your nap was ideal and should improve your alertness for the rest of the day." wtf

I will probably use it for windsurfing only...