"pedo guy", what's that all about, the poster can't even spell properly, that's another level of crazy, stupid for sure.
I just noticed, the 8" to 10" long "submarine" should have been 8' to 10' long, bloody imperial nomenclature, maybe 3m, close enough. Try getting a small 3m long I beam or steel bar through a cave system without bending it or getting stuck. Easy, peice of piss, yeah well go try it then. Easy for big tourist caves, you got a walk way built in. Too many people are being judgemental based on what they read in the press because they don't understand cave conditions.
Go into a dry cave and you can crawl and squeeze anywhere depending on how you can wriggle your hips or ass because that's where you are going to get stuck. Ledges and sink holes, avoid them at all costs because it's a one way journey. My younger brother fell down a mine shaft and his rucksack got stuck half way down, lucky bugger. Slopes, well they're variable depending on the amount water errosion and mud, you can have some grip or bugger all grip. Sumps, your're lucky if they are dry, if they're muddy and there is potential of rain fall then they're are a one way ticket unless you can free dive it back in the dark.
It's caving not rocket science.