Custom Sport Mode with Water Depth Gauge?

[MRC01]

I’d like to make a custom mode for freediving that shows water depth and a few other fields. When I do this in the Suunto app with my Suunto Race, the app has a long list of fields you can display in a sport mode but none of them are water depth. This makes it impossible to do what I want.

However, I know water depth exists because it’s in some of the built-in sport modes.

Advice?