Expedition Navigation Software 
1 of 1- guolin
- Expert
Offline - Registered: 6/18/2019
- Posts: 10
why the optimise result let go over the target TWA?
pls see the attached. why the twa over than Targ?
Thx ：)
- Nick
- Moderator
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- Registered: 9/16/2015
- Posts: 2,740
Re: why the optimise result let go over the target TWA?
Numbers is parentheses indicate tacking or gybing.
For example, (-175) indicates gybing, mostly sailing on port.
There is also a description in the help.
- guolin
- Expert
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- Registered: 6/18/2019
- Posts: 10
Re: why the optimise result let go over the target TWA?
O, Is that mean, we need to sail 150 TWA, but we need to do some gybing. the average TWA will be (-175), so mostly on port, and sometime on starboard.
see the pic. the solid line is exact course, and the dashed line is mean average course (need some gybing).
- •
Thread Starter- Nick
- Moderator
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- Registered: 9/16/2015
- Posts: 2,740
Re: why the optimise result let go over the target TWA?
Yes, exactly. It might be be better for current, wind etc. Of course, the routing chooses what it thinks is the fastest course and sailing to one side might be trivially longer. The reverse isochrones are useful for examining this.