Got the foretrex 201 , very pleased with results, for v.m.g set waypoint downwind about 40 miles downwind, upwind give a - vmg speed . Iv set my display to show turn ie angle to downwind, v m g ,speed, set record to 3 seconds will last 3 races this gives good results on computer, no water under glass yet and at less than £140 is a must, good start function with syn 10 mins countdown then count up, good for all like walking but no map just track and backtrack ect. not class legal but fun for practice 15 hours between charge. iv got 4 garmin units and this is just as good as the rest.

   I looked at the Velocitek S10 but as the waypoint used for v m g is so close it would be hard to evaluate as it is only downdind if you are directly upwind of it?

so WAYPOINT 60 miles away you are allways upwind for vmg.

Only suppied with serial connection no ubs

garmin GPSmap 76CSx  Big Screen Big numbers  and Floats tape it to the mast

Thank you. live and learn, not a lot between them just price and versatility.

i adjust the waypoint 60 miles away to the left or right on the water, it takes 20 mins of sailing to get the feel of the wind as it moves around, then i think you can only evaluate the results on the water,as gusts are not recorded. when the wind is steady and true to your waypoint look back for wind pressure and adjust and play in the middle with no gusts to check for max vmg or just go to opens instead. found that rs600 needs to go very deep to get max vmg. been going too high. but more fun going fast . but slow on handicap