Just lick inside your goggles once you entered that water and that would be the most effective anti-fog you can get...and you won't run out of it. Been using that for years and never failed me, nor it even run out.

BTW, most of the goggles have anti-fog already in the lens. problem is that people tend to wipe inside, hence losing the functionality. next time, just rinse off in fresh water after use and let it dip dry.

my 2 cents worth.