No I don’t mean schools – I mean navigation instruments. In particular, whether we should let our GPS units talk to (and direct) our auto-pilots.
Used to be that the “third rail” of boating conversation (touch it and you die!) was the topic of which anchor was best. But lately it seems that the topic my friends and I disagree about the most is the question of whether to let our GPS units direct our auto-pilots. For me this is a no-brainer, with the answer being yes. But I am amazed at the number of folks with sophisticated electronics aboard who feel this is downright unseamanlike.
When I am doing a single-handed overnight delivery I set my GPS unit up with a route containing a series of way points of my desired track. And since I am going to be using the auto-pilot to steer the boat, and depending on the GPS for position data, it seems perfectly reasonable to me to go one step further and let the GPS direct the auto-pilot by steering to minimize the cross track error rather than to a fixed compass heading.
My standard routine is to check the on-deck read out of cross track error every 5 minutes or so, and go below every 30 minutes to plot my position on the paper chart and check the agreement between the two GPS units and the LORAN. The auto-pilot beeps and requires me to acknowledge any course change when a way point is reached, so there is no question of the boat changing heading without my input.
But while this seems like the natural order of things to me, the majority of my friends do not use their gear this way. They insist on having their auto-pilots steer to the compass heading suggested by the GPS, and then correct as necessary to keep the cross track error to a minimum. Which seems silly to me. If you are going to rely on the GPS unit for position data, and the auto-pilot for steering, why not let them do it?
So how do you do things aboard your boat? Am I off base here, conducting myself in an unseamanlike fashion? Or are my friends closet Luddites who enjoy the magic of GPS but can’t quite bring themselves to trust it?