We keep on arguing about this at our unit. As far as I'm aware, there's two ways of doing a tactical river crossing - which one do you do? I'd much prefer the first. 1) Approach water, strip off out of kit and place inside bivvy bag which also contains your bergan and webbing. This is inflated and you cross holding onto this, plus your rifle, in full gortex (maybe socks but not boots). Cross in pairs or singularily. Re-org other side and go firm whilst conducting admin. 2) Approach water, tie bergans together (everything is waterproofed inside so ought to be bouyant) and cross in full kit first in a pair, then a four, then the final pair. Just tab off again soaked through. I appreciate that the 2nd one is more tactical, and probably quicker, but it'd be fairly demanding especially in poor weather.