A cloudless moonless night sky is not dark like a closed off basement.
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Well your personal millage obviously varies - most people do not know what real darkness is, since they live in well lit areas or where there is lots of ambient light, and it was for them that I described it as I did.
The dark you describe is much brighter than we experienced since we were well-shaded by 10,000-12,000 foot mountains; there was no horizon nor was the Milky Way visible from our position on the beach. The beach at our feet was not visible. It was literally as dark as a closet in a closed off basement. Pitch Black.
If you were witnessing something in the sky above you then you had horizons. The horizon may have been closer than if at sea but you had horizons. Could you see any stars in the sky overhead?