Was recently diving in the Philippines and woke up to a (mildly hungover) shock the next day. I was brushing my teeth and spit out dark charcoal gray foam. I stuck my tongue out and the entire surface was pitch black. I'd done two tanks the day before,neither of them tasted smoky, deepest dive being a shipwreck at 90ft ish, so I poured over my DAN dive med guide convinced I had some sort of weird DCS. Found zero mention in anything at all of a black tongue, and on closer inspection it was just the srface, no discoloration anywhere else on my tongue. I used my toothbrush to remove all of it fairly easily, and it hasnt come back. but I'm still wondering why the hell my tongue turned black.
