My chartkits are on top of the water
tank in my cabin
-- there is 4" between the top of the tank and the bottom of the berth, so it made sense to make use of that flat surface. Years ago they were stored behind a bookcase my dad built -- wedged between bookcase and bulkhead. Smaller chartkits (the half-sized ones) are in a drawer of the same bookcase.
I prefer to store flat (versus rolled)
I've seen them tucked under unused bunks in cabins and some folks have them against the bulkhead where their feet are by the nav-station. A piece of Plexiglass holds the charts flat.
My considerations for placement were dryness (no mildew or drips/dampness) and I didn't really concern myself with accessibility as these aren't an emergency
get-to right away item. They are out and in use. When I get near (within a week) of the next chart, it comes out too so I'm ready.
Good luck and enjoy your new boat.