Hi

(I haven't purchased Expedition Navigation Software yet. I still have some questions.)

When I watch some polars diagrams , I see few lines on a same graph, depending TWA/TWS/SOG (hypothesis there is no tide). OK, but ....

For each TWA/TWS, the difference between COG and HEADING is not the same : drift.
(drift more important if wind (AWA) from side than TWA=170°... but not only...)
And TWA depend of the axis of the boat (so TWA depend of HEADING).
So, when Heading=0°, COG=6°, TWA=x , TWS=y, Bearing to Waypoint = 0°, SOG=10kts, it's not true to make a polar with SOG=10kts : Approach speed to waypoint (VMC) is a trigonometric result of 10kts (I didn't calculate but it's easy).

My first question : 
Is Expedition Navigation Software calculate polars from VMC or directly to SOG ? I fear ("fear" ??) the drift is not considered, so in this hypothesis only TWA/TWS/SOG/Heading would be considered.... so polars are not exact.

My second question :
If heeling increase too much, drift increase too. So VMC decrease (SOG can be constant or "not enough"). I read that Expedition Navigation Software have "advanced polar", is this software considering heeling (so drift, so vmc, so....) ?

My third question :
Can Expedition Navigation Software display (feature) "Beat heel" ? (I think is not very important if the software display "beat COG and Perf%" but maybe yes...)

My fourth question :
(​I almost forgot). Adrena software can calculate polars in realtime (I don't know regarding my two previous questions). Is Expedition Navigation software calculate and improve polars in realtime ?


Waves (height and direction) and tides are another subject (ok important for diagrams polars but another subject).

Thanks for your answers.

(sorry again for my bad English)