These days my chart plotter (B&G Vulcan) remains on as the
radar (Simrad) is connected and operated by the plotter. It is usually in standby conserving energy but is almost instant on when required.
The plotter isn't connected to a
depth transducer, I purposely have a
fishfinder (Lowrance) for
depth only which I turn off when not in soundings which saves
battery power and I am sure is dolphin and whale friendly that way.
The plotter also keeps tally of my logged distance run, as well as
wind speed direction overlay on the
screen which runs C-maps for charting.
My back ups are numerous (old school) since I began cruising in the 1980's