I think this is a 50’s-60’s sci fi movie. There’s a guy walking through a swamp-like area, with some fog, and some foam/bubbly stuff he’s walking on. He’s wearing some large snowshoe-like things to keep from sinking. I think he’s got a beard, and is dressed for cold weather, but that might also just be old-school “always wear pants and a long sleeved shirt” thing.
It seems to be set in the 1800’s or early 1900’s, I remember them being on a boat/ship that somehow gets through the swamp. I think there are several people on the boat, but the man is walking alone at this point.
It’s dark-ish (like a dull glow, not pitch black), and green-yellowish tinged if I’m remembering right. So I think it’s color, but not 100% certain. It feels like a Jules Verne exploration and adventure sort of story (I didn’t find a Verne movie that matched, but might not have gotten them all).
I saw this in the mid 90’s probably, pretty much had to be on TV but maaaaybe was a bit later and on a computer. Definitely wasn’t at a theater.