Page 85 of PADI's Adventures in Diving Manual, which is the PADI "Advanced" diver manual, has a pretty egregious typographical error.
I like diving with Imperial units. There's exactly one substantial reason to like Imperial rather than Metric. That is: the safe ascent rate in SCUBA is one foot a second. Nice and easy. 1'/sec. With Metric it's like 3 meters/10 seconds or some such thing. I don't care. It's dumb and there's no way to just think it rather than looking at your dive computer. One foot per second is the speed I need to know. I prefer to work entirely in Imperial because of it.
Yeah, I wouldn't care if the pressure in the tank were in cubic litres or whatever. But depth is gonna be in feet baby. There. I said it. So be it.