Ocean deep meter

There's 3 units of measure for Altitude in the game:

• Above Ground Level (AGL)
• Above Sea Level(ASL)
• Above Sea Floor(ASF)

ASF will tell you your exact height above the sea floor(or ground level if not underwater) and by subtracting your height above Sea Level(ASL) from the ASF, you'll get the exact depth of the water at your position

maybe on the mfd display to know the depth in meters