I noticed this while playing with this and I tried various different areas and also compared to several ABC watches I had in the house. The standard compass on the Fenix 5/Descent line allows for you to choose between Magnetic North or True North. But I’m noticing the compass in the “Dive” mode, only reflects “True North”.
There should be an option in the “Dive Settings” to choose between Magnetic or True North. I’m a Dive Instructor and one of the big allures to me going with this watch was the underwater compass options with the Direct Bearing, Recp. Course, etc for guiding students but their compasses will reflect Magnetic North, while the MK1 reflects True North.
