It's a good question. You know what they say about stupid questions and/or people..to my mind, the only stupid people are the ones who never ask the 'stupid' questions.
As to the answer, it's pretty intuitive once you think about if from a survival perspective. The autopilot
is, indeed, like replacing tiller/wheel manners for the majority of the trip...so long as it's working. All of the long-distance singlehanders have had major issues with their autopilots at some point. I consider myself lucky that the only problem I had in a nonstop ~7,000nm leg was a little bit of rust on my DC motor's brushes
that I had to clean off, which took about four days for me to diagnose and repair (I have a big, clunky hydraulic steering
unit rated for a boat twice this size, and the accompanying motor
is fairly powerful, not to mention fairly inaccessible).
So, when you're like me and about 2,000 miles into a 7,000 mile trip and contemplating pulling in for a God-knows-how-much-it-will-cost-to-repair situation, or doing the whole 14 hours on, 10 off routine for the next 2+months, you feel a little bit like you should regret the decision to go sans support crew.
The other reason is safety
. The autopilot
is a wonderful piece of machinery, an essential one, really. But it's not a full crewman. If you need extra muscle to deal with an emergency
, or another pair of hands to be somewhere while you're somewhere else, the autopilot can't help you there. The autopilot also doesn't have any eyes or ears (unless you count the compass
it uses as a sensory organ), so it can't help you to spot floating containers, reefs
, or other vessels. It also can't see squall lines coming, which can result in some hilarious moments in the middle of the night where you're not sure if you're actually awake (in the middle of 40+ knots with a protesting autopilot) or just having a nightmare.
Most autopilots can handle reasonably balanced sailing without big issues. It's best to get one that's specifically designed for sailboats if possible, at least in my experience, because the compasses they use on sailboats are a bit better gimballed than the more simple powerboat versions, which really does matter when you get into bouncy seas or trying to run downwind while your boat rolls side to side. Cuts down on unit wear and tear, and also decreases electrical consumption
having a well-gimballed compass
That's all I've got.