44 ST4000 PlusWheel & Tiller AutopilotsOwner’sHandbookAutoTack angleThe AutoTack angle is the angle through which the vessel will turnwhen automatic tack is selected (see Chapter 2). The value must bewithin the range 40 to 125∞, and can be adjusted in 1∞ steps.AutotrimThe AutoTrim level setting determines the rate at which the autopilotapplies ìstanding helmî to correct for trim changes caused by varyingwind loads on the sails or superstructure. The settings are:Setting Effect Recommended for:Off No trim correction1 Slow trim correction Heavy displacement vessels, withfull keel or transom rudder.2 Medium trim correction Heavy displacement vessels.3 Fast trim correction Moderate to light displacement vessels.4 Super fast correction Planing power vesselsThe default setting (Level 3) should provide optimum performancewith the ST4000 Plus autopilot. However, depending on the vesselísdynamic stability, an incorrect rate of trim application may result inpoor course keeping due to autopilot instability. After gainingexperience with the ST4000 Plus, you may wish to change the setting.The effect of the setting must be evaluated while under sail.
