Sebastien Murat (Seb the Sub) is a freelancer with a special technique. Before he dives, he breathes up to half of his lung capacity (exhale diving). For him, this has several advantages, or circumvents it with this technique is problems that freedivers who push into extreme depths have to ask. Seb explains his technique in this film and why he uses it. In another interview, Sabastien explains the mammalian diving reflex, which is still active in humans and how the apnea divers take advantage of it.