I agree with Jim, Nigel and Pelagic.
I think NAV is a great facility, provided you don't overuse it, and provided you don't underuse it.
I would certainly set up a route in circumstances as described by Jim - I think it's a great way to use the technology - but I would want to have already become well familiarised with the procedures.
And to have scoped out the pitfalls under more forgiving circumstances.
And, like Pelagic, I see a lot of value in "flying the plane" for a portion of every watch.
And not just for the excellent reasons he gave: if I have to be there, keeping watch, I personally (and rather untypically) find it less
boring if I am taking part in the process of sailing the boat.
In bad weather
, it helps me sleep when off-watch, if I've "done a few rounds" with a punch-drunk helm
Plus it can be fun, and instructive, trying to steer 'like an autopilot'.
In other words, making up and testing rule-based algorithms.
Two of the best I've come up with both relate to reaching and running in hard weather
Under one routine, I adjust the phase, and the 'profile', of my steering correction relative to the run of the sea, until the boat stays under the mast
(By "profile", I mean the waveform of my correction. It might for instance have a sudden onset and a slow decay (usually works better) or a slow onset and a sudden decay. By phase, I mean shifting the timing, sometimes almost 180 degrees out of phase with the 'natural' tendency)
Under the other routine, which works best on high performance sailboats, I monitor
the attitude of the boat in pitch
rather than heel, by comparing the pulpit against the horizon. A simple mental image of a hoisting rope
, attached to the bow, running up to a pulley in the sky, and then taken to one side of the wheel
, sometimes (often) works a treat, keeping the boat under the rig almost as well as, and with less mental effort, than the other (more powerful) routine.
Where this sort of practice really pays off (apart from racing
, with a spinnaker
, on the hairy edge) is when someone has to go up the mast
in bad conditions to effect a repair.
But it also makes life on board more pleasant for those below, and more interesting for the person on the wheel. Watches seem to pass quicker when you're learning
, and I would rather it was me doing the learning
than the autopilot.