It's because of the mix of an elecrtonic and a mechanical solution, as the Depht Gauge woks with a battery.
I understand that it was the only solution ot get some official authorisations, but I much prefer the whole mechanical JLC Depht Gauge.
I aslo have to say that the esthetic of the Panerai Depht Gauge is not my cup of tea.
But..To each its own...
Best.
Nicolas