I have never actually fallen in, but have got wet on numerous occasions . By far the commonest was wading an inch or more deeper than my waderr length. A bit of a laugh in thigh waders, less so in waist waders, and getting a bit hairy in chest waders. Done that in many rivers and in surf. If you ever don chest waders It is very important to invest in a good stout wading staff, both for feeling your way in a rocky river, and providing a third leg in a dodgy current or surf. Once you get chest deep it is easy to get knocked off your feet by a wave or a current surge. At 86+ my wading days are well and truly over,
Have also had to swim for it as a result of a canoe collision - a canoe shot out from a side stream and rode over our stern and Norma's leg. (Incidentally Tigger this was in Madagascar, not the Amazon) there is an account somewhere in the AN archives.
I have however once been washed in. There was e deep pool into which the water ran through a culvert . Just where the culvert entered was screened by overhanging trees and bushes, so the only way to fish that spot was to approach through the culvert which was brick-lined. This I did in pair of rubber-doled thigh waders. Slipped on the slimy bricks, which deposited me on my gluteal adiposities (fat a### in English) blocking the culvert and promoting a build-up of water behind me. This washed me out into the pool. I remember thinking how ridiculous the incident was, and burst out laughing as I was washed in. Got out easily enough (did you know it is perfectly possible to swim whilst holding a fishing rod ?)'