Simrad CE34 ChartSounder Manual page 126

Chapter 8-6 CE34/44/54 Setup menu
Start position - can be inserted if the exact start position is known.
Speed and course filter level - there is a filter of 10 steps available
(0= fast response, 9= stable readout).
Display speed as - SOG Speed Over Ground or STW Speed
Through Water. Toggle with +/-.
To receive STW information will require connection of external
instrument via the SimNet system or the NMEA port.
Course and bearing as - readings of course and bearing can be
made in either MAGNETIC or TRUE. Toggle with +/-.
COG vector length - (default to 6 minutes) - indicates own course
and speed. The length of the COG vector reflects a distance run
during the specified number of minutes at the immediate speed.
Time - can be set to UTC or local. Toggle with +/-
Correct actual time and date by means of the numeric keys.