well, both of you please CALM DOWN !!!
1-Infantry don't train at sea or deep water, especially Airbone
2-It's true that it's tough for a poor infantryman to get rid of his stuff, but the packsack is the easier part...
3-Well, those kind of boat wouldn't flip easily, and soldier rarely fall from it, yeah btw, there's no country wearing floating equipement when training with combat gear.
4-Combat gear are rarely weight over 25lb without rifle. I take my exemple, my combat vest weight maybe 2,5lb, 3lb for the canteen, 2 lb for 2 hand grenade, 7lb for the food and plate,10lb for ammunition, 2lb for a radio and etc... So a typicall combat load + a pack sack will be in the 50lb