Hi Ed,
I thought about this a little after last posting here. One important thing to remember is that you might have this issue if the currents, winds, etc. are contributing to what you're experiencing, and if you're simply going too slow. Steerageway can be a little difficult to reach if you're going very slowly with winds and currents trying to push you in different directions. That will make it harder for the a/p pump to control the boat. One way to check that is to test the system by going directly to windward on autopilot and then setting a relatively low speed. If the wind and current are coming from relatively the same direction, that will help as well. If the boat is able to hold a heading, then you know currents and wind were a contributing factor previously and the system is fine.
Another important thing is what you mean by slow. With SOG In the 4 knot-range or above, you should be ok with a little wind and current trying to push you off course. But anything around three knots SOG or less will pretty much be a challenge for the AP system to correct if the wind and current are not cooperating. Let me know if that makes sense and what you find when you get a chance to try it out.
Cheers,
Ralf
