Know before you go - AdventureSmart

Today, at 11:43am local time in the Bahamas, New Zealander William Trubridge dove 100 meters into Dean's Blue Hole on Long Island with a single breath of air and only his hands and feet to propel him down and up.

This historic depth, also known as one hectometer, was first reached in 1980 (the year of Trubridge's birth) by Jacques Mayol, famous for being portrayed in the movie "The Big Blue." However Mayol used a weighted sled to descend and an inflated lift bag to return to the surface. Trubridge wore no weight for his attempt (just an Orca wetsuit), and swam underwater breaststroke next to a descent line, which he could use as a guide only. At 100 meters he collected a tag as proof of depth (the depth is also validated by a Suunto depth gauge he wears on his wrist), before swimming back to the surface.

It was William's 13th freediving world record, and set on the 13th of December. Thirteen has traditionally been a lucky number for his family, who set sail on Friday the 13th of January 1982 to cross the Atlantic and Pacific oceans to arrive in New Zealand, where William and his brother Sam were raised.

The dive attempt, called Project Hector, was dedicated to the Hector's Dolphin. It is the littlest dolphin in the world, and the only one that is endemic to New Zealand, but the species is threatened with extinction, and a bill being considered by the Minister of Fisheries could determine its fate.

William writes:

"Four years ago it took me three attempts before I set my first world record freediving without fins. Since then I have come a long way, both in depth (from 80 to 100 meters), and in my confidence and capacity to perform under pressure. I needed all of that experience today when I made my third attempt at the historic depth of 100 meters.

Yesterday I had already touched the mark and come back cleanly, but a technicality (not taking my noseclip off during the surface protocol at the end of the dive) meant that the dive was disqualified. During this dive I managed to tweak a muscle in my neck, so overnight I took a lot of anti-inflammatories and propped towels under my back and neck while I slept (thanks mum!). This morning we awoke to a turn in the weather: a cold front moving across brought chilly winds, and blotted out the sun. I entered the water at 11 in the morning and immediately started shivering. At the end of my breathe-up, as I turned to start the dive, some of the air in my lungs was forced into my mouth, and from there into my stomach. For a split-second I contemplated continuing, but it would have been foolhardy, so I aborted and rolled back onto the surface with a groan of dismay.

There was still a glimmer of hope to save the day, and I quickly went ashore, climbed into my car and turned the heating up to the maximum setting. After roasting myself for twenty minutes, I returned to the platform. This time I spent less time breathing up in the water, and turned carefully to start the dive. After that moment I have few memories, as my body was operating on autopilot, as it has become accustomed to do in deep dives. I remember relaxing as I entered the freefall, and telling myself to 'relax even the potential for contraction.' I remember my depth alarm going off and pulling the tag from the bottom plate, 100 meters below the surface. I remember keeping my eyes half-closed and telling myself to 'relax' and 'flow' as I set off on the long swim back towards the light. I remember coming to the surface, reminding myself to concentrate on doing the protocol correctly in order to ensure a valid dive. And I remember erupting into celebration with my team the moment the judges displayed their white cards.

It has been a long road to this magical depth, and I could not have done it without the support of an incredible team: deep divers Brian, Paul & Jason; safety freedivers Alfredo, Brian and Charlie; photographers Igor and Paolo; paramedic Tom; Nic, who traveled for 2 days from NZ to support me; and my loyal and loving wife and coach Brittany.

Thank you also to the event sponsors Suunto and Orca - their support for myself and the sport of freediving has been incredible. Thanks also to my other athlete sponsors Ex Drinks and Tenerife Top Training, and to Glorope for supplying the perfect freediving cord."