Hi LKorzilius and Djwpe,
Good questions - one of you worried of being too high and the other too low!
Angles;
I use a Tacktick Micro Compass and have it a Tactic mode with 5' increments. On any particular day it is important to pre-set the tacking angle so that it 'balances' to read the same on each tack (displaying the direction of the wind).
With the RS Aero 7 rig I adjusted it to 70' at the Lymington Regatta (medium /light wind with flat water) and then didn't change it again during the Nationals two weeks later.
The RS Aero 9 in flat water and a medium/light breeze (slightly underpowered) will point as high as a 65-70' tacking angle.
Even in waves and either a very light or a very strong winds I don't think my tacking angle exceeds 85'.
Rigs;
RS Aero 9s point a little higher than RS Aero 7s ,which in turn can point a little higher than RS Aeros 5s. This is due to the power available and also the balance of the boat (more sail further back on the larger rigs).
Conditions;
In flat water you will point much higher than in waves as you will be able to hold the 'knife edge' longer without interruption.
In waves, each wave you go over will slow you, so you are continually looking to regain speed in acceleration mode (more free angle, more open leach) and having to steer around the waves rather than slamming in to them.
In a shifty gusty breeze you might point high for short periods, until you need to accelerate again - hence more using mainsheet rather than kicker tension to be able to adjust the leach tension more dynamically.
Preference & flexibility;
Different sailors prefer to sail in different modes, and different modes may well produce very similar VMGs whether low and fast or higher and slower. Whist a sailor may have a preferred mode it is also important to be able to do both effectively. That allows good lane holding and tactical options. If you are about to be rolled off a start line you may need to sail low and fast. If you are being lee-bowed you will need the ability to point high whilst you are unable to tack. Similarly when over or under a lay line.
To point high;
- Cunningham off (tightens leach)
- Mainsheet tight
- Flat boat -reduces leeway, although sort term heel will help the boat want to luff)
- Weight slightly forwards
*Beware - as soon as the speed drops be ready to bear off and open the leach (mainsheet/kicker) to accelerate again.
To point low;
- shoulders back
- tweak the tiller towards you to fully power up the sail and judge whether the increase in speed is is beneficial given the lower angle.
*Beware - of all the pointers climbing up inside you!
I hope that helps!
Time on the water against other RS Aeros will be key to developing feel and judgement of the best VMG angles and how to achieve them.