deviation chart

[GordMay]

What John (MidLandOne) said.

I’d be happy to steer to within 5 degrees of my intended compass heading; whereas Maggie seemed to be able to steer incredibly accurately (±1-2 degrees?).

Given that the typical steering compass is only graduated in 5 degree increments, and identified in 30 degree increments, anything smaller than a 5 degree difference is a visual estimation.

Generally estimated values, Set & Drift introduce further (unknown) errors into our reckonings.

Any calculation should only be assumed to be as accurate (at most) as it's least accurate component value.

Of course, there’s no reason to deliberately add MORE inaccuracies/unknowns to our plotting & steering computations.

[David M]

I am of the belief it is best to remove as many sources of error as possible. Error tends to compound itself. I would gladly take one source of error over more sources of error any day. I understand that for small boats, a +/- 5 degree steering error by the helmsman is pretty normal and steering better than that in anything less than calm seas with the helmsman concentrating is unrealistic.

This all seems to boil down to how good is good enough?...and that is a very subjective thing depending on the individual.