My new Simrad AP28 autopilot is up and running and Betty Jane seems pretty proud of her new, steering-related capabilities. Just a few days ago, I dialed up Simrad's new No-Drift Mode on the unit (which I affectionately call Otto, by the way) and it worked like gangbusters, holding Betty right on course, despite the considerable effects of wind and current at the time.Now, if you want to read all about Otto and the entirety of the saga of his installation--and I do mean saga (adapting a Post Modern autopilot to an old-fashioned boat requires quite a lot of work these days and I should know since I did most all of it myself)--you can crack open an upcoming issue of Power & Motoryacht, although I'm not sure which issue yet. But if you're only into grabbing a sneak peak at this particular time, read on:
No-Drift Mode? Imagine that you are creeping along a fairly tight little channel that's fraught with a sideways current. Of course, in order to stay in the channel you'll have to "hold up" (as we used to say in the ship piloting biz), meaning you'll have to steer into the current slightly to make good on your course and maintain a safe position in the channel.
The way you deal with this sort of thing with an old-fashioned autopilot is you play around with the number of degrees you use. You try two degrees for a while and see if that keeps you in the channel, then maybe you try three, or four, or whatever, and finally settle on a heading that seems to do the trick--say steering 93 degrees to make good a course of 95 degrees. However, if the strength of the current changes for any reason, as it often does, you have to go through the trial-and-error process again.
But hey! The AP28 does away with all this complication. You simply dial up whatever course you need to follow to get from where you are to where you need to go and the autopilot does the holding up for you...automatically.
And guess what! When the amount of sideways current effect or set changes (even if it gets pretty darn strong), the AP28 adjusts and keeps you on your heading nevertheless. All by its lonesome.
Is my buddy Otto cool or what?
