Dont worry too much. There arent many water activities in army
actually. For BMT, they will separate u into swimmers and
non-swimmers. For non-swimmers, you will go for swimming lessons
that are conducted in medium pools, not deep pools, which means
your feet can still reach the bottom of the pool. And if you think
you really have phobia of water, you can tell your platoon
commander. I have some friends who got away with this excuse,
provided you are convincing enough and your platoon commander is
taken in by it.
After BMT, you wont have much chances of water activities, unless
you are being posted to the more elite combat forces where they
have things like 2km swim, river crossing, diving etc. But even if
you really sway sway kenna posted to such a unit, dont worry. All
the combat water activities come with inflated life jacket. You
will never drown unless you didnt wear the jacket properly or the
jacket is damaged.