Remember when you used to hang out in your mate's pool and have those all-too dangerous competitions to see who could hold their breaths the longest? This is like that – just, you know, professional. Technically, it's called "competitive apnea", in which competitors attempt to go the greatest depth, distance or lengths of time on a single breath... under water. See the best at this special event as part of the Oceania Dive Travel and Watersports Expo. Free with Aquatic Centre entry of $3.50-$22.