All you need for your own water warfare games are a few basic supplies.
For shorter games, or games with only a few people, you'll usually only need
one water blaster. For longer or larger battles, gear up with a main blaster
and a "back-up" blaster. Extra "ammo" (some water bottles or a bucket filled
with water) is a good idea too.
Of course, all gear is optional, it's up to you and how you want to play the game.