Chris..the windex does indicate apparent wind, when moving and true when stoped. (mine disappeared some time ago, new one already on order, want to go up the mast install it??), but the ST60 indicates (well mine used to, but now only indicated apparent due to a faulty wire, according to what Tom found when there) both apparent and true with the boat moving.
Just a side note
Chris G I know you know this but this helps others)
is the wind speed and direction one feels with the boat fixed on a point, that is when its not moving, and apparent wind
is the wind direction and speed when boat moves, modified by all the different vectorial changes that occur once the boat moves.
On an closed reaching the apparent wind moves towards the bow, decreasing the wind angle, and the indicated wind speed increases, reading therefore lower tack angle and higher windspeed.
On a wide reach (whatever its called in English), the apparent is also forward, but the wind speed indicated is lower. When we move towards the runing the apparent wind will almost drop as a consequence of the boat moving with the wind.
When I meant 25º it was really true wind. Normally boats will start, under normal conditions at 30 to 32º. I can get just a little bit more. Off course you must understand I can pretty much do what I want with my sails and mast configuration to help.
I have done many runs, almost a year ago when we first started sailing my boat..
We've had many cases, and we did thsat to develp the polars for my boat.
In one instance with 15 knot true wind, we were doing around 4 to 5 knots, at exactly 25º true. The apparent wind was indicating around 18 knots wind speed apparent at 20º off the bow.
Normally in 25 to 30 knot winds, (true), we can sail at 8 knots, and be pointing 25º true. This is around 20º apparent and indicated apparent wind of 35.
Either way, I can still move at 25º apparent or 25º true.
When Tom and Mark were in Portugal, last week, we were doing a relaxed sailing at 20º apparent, with 20 knot winds apparent, and speed over ground was 7 knots and according to my calculation, that is already 29º off the true wind.