Reading Depth Soundings

When you are seeing a depth number [sounding] with multiple digits where it looks like you have one larger and one smaller number, treat it as a decimal.

Example: 10₃
Larger (regular font) number = full depth unit
Smaller (subscripted) number = 1/10 depth unit
Where your depth unit is set up on the chart plotter or mobile app as feet or meters.

Example: 
10₃ = 10.3 =
Depth Unit Meters = 10 meters 30 centimeters
Depth Unit Feet = 10 feet 4 inches
Depth Unit Fathoms = 62 feet