I’m not sure about “impressive,” but definitely marvelous, and humbling. Just last month, we were on a night dive on a wall in Misool. We'd already had a great dive; nudis, of course, and several parrots in their night dress, and crabs; and then a beautiful, large (80-100cm? I'm sure it is the largest I've seen) scrawled filefish swam up to me, between me and the camera! for scritches. I moved it along after a few seconds, and it swam straight to Nancy, a few feet behind me, and wanted more pets. Naturally, we try not to touch . . . but, hey. So that was cool. A few minutes later, about 55 minutes in, my camera was almost out of battery (dumba$$ didn't change it after the third dive) when our incredible guide started flashing his light at us. I got to where he was, in time to to find a walking shark coming up beside him and then duck into a small cave. So, that was really cool. I turned the camera on, but I'd already shut the strobes down (we were on our way to the skiff, after all); still, I got a couple of shots in the beam of the headlamp I was wearing. The battery was at about 6%, so I shut the camera down in hopes of gaining another shot. Then the walking shark swirled around in the cave, and came out straight at me. I had enough time to hit the power button, and managed to get a shot off, again with the focus light. I'm pretty sure I didn't have my eye on the viewfinder, but it wouldn't have mattered. The image was very (profoundly) underexposed, but the OM-1's RAW engine let me pull out this detail.
Here's what it looked like the the little cave (also crazy underexposed).
So, it swam on. A few minutes later, a second one crossed in front of us and . . . well, walked . . . up the slope. Our guide said that they are known to mate at night in those waters, so perhaps that's what was happening. Anyway, the camera battery was at 3% when we got back to the liveaboard, us left to reflect on how unimportant we are down there, and how little we know about it.