st60 close hauled wind angle difference by tack

[Ricd]

Hi
I recently had new standing rigging involving removing mast (probably first time in 15 years). The rigger mentioned at the inspection that the mast was slightly mis-aligned, probably from first stepping, and he would corrected this during re-stepping. Anyway, I have found that my st60 now reads about 25 degs apparent on stb close hauled tack and about 45 on port. ST60 calibration is designed to overcome small differences due to accuracy in fixing vane wand to mast. It says drive boat into wind, enter calibration and use tack and app/true buttons to adjust display pointer to zero. Was wondering if I could simply adjust this while tied up in marina with wind say on or close beam by just adding about 10 degs rather than prating around at sea and probably falling out with crew (wife) who would either need to steer into wind consistently while I sort out the adjustment or visa versa?

 

[RichardS]

I've done that in the past. Adjusted it in the marina by the amount that I know it's out ..... and then checked it next time out at sea.

However, I am amazed that tweaking of the mast alignment would case that much error .... although I'm not sure what "mast alignment" really means so I could be talking rubbish.

Richard

 

[Ricd]

Thanks for that, was pretty sure it would work but good to have you confirm i am thinking along right lines. ..wife is a bit miserable about me always tweaking things at sea.
Don't think the issue introduced by re-stepping more squarely is as large as 10 degrees. I have already been living with a small biased showing on the instrument between different close hauled tacks. Think the re-stepping just added to it such that in now seriously annoyed me to the point of fixing it.

ta

 

[Norman_E]

Possibly the mast head unit was knocked out of kilter whilst the mast was down, or when it was being put back up.

 

[Pete7]

Possibly the mast head unit was knocked out of kilter whilst the mast was down, or when it was being put back up.

Ours is like that after we hit a tree with the mast head.

 

[Ricd]

Adjusted instrument in marina with wind at about 120, took 10 degs off then took boat out for sea trial over last few days and wind instrument now working perfectly with both tacks reading 30degs close hauled.