Raymarine S1 autopilot autotack ?

[PembrokeshirePromise]

Just been playing with this over the w/e.

All goes well on one tack (going to wind) - and it holds the boat fairly well to say 35 degrees to starboard off the wind - and the display says as much - and the compass course adjusts with any windshifts.

The autopilot is set to tack through a given angle (100 degrees by default). However when you use the autotack function - it tacks through the prescribed 100 degrees - meaning we're sailing about 65 degrees off the wind (compass heading correct) - BUT - the display says its trying to keep us to 35 degrees to port - which quickly gets an off track alarm

I don't understand what its trying to do. Surely it should
1) Either tack through 100 degrees each time - but then it should adjust the angle its trying to keep to the wind 35 degrees on S and 65 on P (which would mean a rather uneven tack) (ignoring any apparent wind issues)
2) Or - tack through the wind to put you on the same tack on the other side - which is what the angle to the wind indicator suggests - but its not doing ??

Seems its having an internal conflict.. I guess the way to sort it is to set it to say a 70 degrees tack angle and always tack at that angle - seems a bit limited though - surely the default tack should just be the same angle on the other side.

Anyone else got one of these and can shed some light - have I missed something ?

Thanks

 

[Talbot]

unless you are stationary, a tack from 35 deg on one side, through 100 degrees is def not going to end up at 65 deg other side, final angle will depend on wind and boat speed, but may be only 45 deg other side. Suggest you reread what you have set up.

 

[PembrokeshirePromise]

Ok - yes I take your point and you are right - you do end up on about 45 - 50 degrees on the other tack - but that doesn't alter the fact that the autopilot still says its trying to hold a bearing to wind of 35 degrees - but with a compass heading of 45-50 degrees off the wind (as the reuslt of a 100 degree tack)

I just don't quite see how the two can match as the bearing to wind is always the reciprocal as you tack - regardless of what the tack angle is set too /forums/images/graemlins/confused.gif

Or have I missed something basic here..

Thanks

 

[Kylora]

This a quote from the on line manual

How do I use AutoTack in Wind Vane mode?
Note: If you use the AutoTack function in Wind Vane mode, make sure the wind vane has
been centered accurately.

See Here

Ash

 

[PembrokeshirePromise]

Thanks Ash,

I had seen that - but it is - the wind vane shows 35 degrees on one tack and then c.50 degrees on the other (which is correct)

My issue is that there is no way you can always be on a reciprocal bearing after a tack if you are also tacking through a fixed angle (unless you assume you always sail as close to the wind as possible in which case you could set it to work)

The display head seems to contradict itself with the 2 figures it displays - or shoudl I just give up and press +/- 10 half a dozen times ...

 

[Talbot]

suspect that you may need to alter from wind vane mode to compass mode prior to tack, then after tack has settled down, revert to windvane mode.

 

[PembrokeshirePromise]

Yes - that sounds a sensible idea - and I'm sure would work - I was just probably fixated on thinking I should be in windvane mode for autotacking - but maybe thats not the case at all

 

[PembrokeshirePromise]

Just re-read the manual yet again and I see:

"When you AutoTack in Wind Vane mode, the boat turns through the AutoTack angle. The SmartPilot will then trim the heading to mirror the locked wind angle from the previous tack."

I was tacking up quite a confined waterway - so may not have been giving it enough time to come back up to the reciprocal angle. What with wind and tide - I was almost going backwards on each tack - so took over !

Need to try in a bit more space and be a little more patient maybe - however a case of RTFM I fear ...

Thanks to those who have replied

 

[AlistairC]

I have one of these.

If you get into the calibration mode, you can adjust the number of degrees course change for the autotack function - it comes as default 100 degrees but should be changed to suit your vessel.

 

[ytd]

I always use compass mode in confined areas. The wind mode takes longer to settle down after each tack and seems easily confused in light winds or by windshifts. I have set 90 degrees tacking angle but 100 might be better as you can get in irons if you have to tack when lifting.