Simrad CE34 ChartSounder Manual page 86

Chapter 6-4 CE34/44/54 Miscellaneous menu
The scale for the speed diagram can be adjusted in this display.
Time interval can be set in 8 intervals from 1 minute to 3 hours and
freeze.
Go to the function you wish to change
Key in new figure or change setting
+/-
Confirm entry and return to Speed diagram
ENT