Luckily, I have a friend with lots of bubble guns, wands and bottles. These items were called for at the 2011 Bubble Battle which took place out on Coney Island, the same day as the Mermaid Parade. So my friends and I watched the parade, got some franks, then prepared to duel.
But it wasn't so much a battle as a medium-sized crowd simply blowing bubbles and getting soapy water everywhere. Either way, we had a blast!