Right of Big Mossy gets boney @4k, pinball/mine field after that. The left slot is always there, down to 1700 (lowest I've ever seen it, wouldn't want to take a snout down there at that level...).
Above 6k the right run comes out, it's easier to see but the right eddy can be tough to time correctly and A LOT of water going back upstream there. You need to be on the fence, and just break out of the tail of the eddy over "home base" (barely submerged flat rock at the top right, bad baseball analogy but that's what it's always been called). If you touch home base and just line up to take the big right lateral off your right bow you don't have to take a stroke, just keep pointed downstream and you'll squirt out the bottom clean as a whistle...
Low water Cataract is really good to learn to read water on. The "just left of Niagara" line in the video is viable at different levels, there is also an "all the way right" slot there (similar to Skull in Westwater). "Conventional Wisdom" is to run it pulling right just after the big rock on the left, it's a nice tuck in there move I prefer (usually). Sets you up nicely for the tailwaves of 2, which are great fun.
I've also seen an S-rig lose its motor at the bottom of BD1 and watched swimmers go over Niagara at 65k+ - they were down there for a solid 30 count, one said he touched a sandy bottom (not sure I believe it but he had no reason to make it up... eyes big as saucers). The boatman on the motor told the pax to jump when he lost motor and they were deadheading into 2, there were 12 swimmers and two who stayed with the boat, incl. the boatman. It didn't flip in 2 or 3... Go figger.