I had my own way of submerging into somebody's birthday party.... Well theonly way to do it with an underwater celebration is to do it freediving.
Totally shocked the whole bunch.
Was told that the depth is at 12 meters. Was at that depth for a good 10 secs before the lactic acid kicked in. No device to time but i think i was underwater for 20 secs.
Credit to peng song for the picture. I'm the one with out the scuba gear & tank btw :P