Simrad AP28 Operator's Manual page 30

You can at any time change the main course.
You can also at any time change the distance of the leg
until the boat makes a new 90° turn.
30 | Operation
Turn parameter
Leg distance
The unit for leg distance is the same as the unit set for
depth (feet or meter).
MENU
Range
82 ft - 9843 ft
25 m – 3000 m
Change
Default
per step
50 1641 ft
25 500 m