As reported on Phil Simha’s blog Herbert Nitsch did not attempt his 244 m/ 800 ft dive yesterday. He is, however scheduled to dive on June 6th, and when the world champion dives he will be relying on the freediving specific Liquivision Xen dive computer. Adapted from the field-tested scuba diving Xen computer, the Freediving Xen is the world’s first dive computer to incorporate detailed decompression calculations for freediving with custom software for freedivers. The decompression calculations are useful both for repetitive dives (for example spearfishing) as well as for single deep dives. For spearfishermen, the main utility is to inform the diver of the required surface interval before the next dive, and to check for violations of the Xen’s unique variable ascent rate limit. For competition and record divers, the Xen not only provides the diver with a live calculation of the required enriched air decompression schedule after a deep dive, but the diver can use the planning function to actually plan the post-dive deco before even doing the dive.
The Xen incorporates an OLED display visible in complete darkness, with a 170-degree viewing angle. This allows freedivers to read the computer during an entire dive without barely breaking the streamlined position– making audible alarms no longer necessary. Even diving with fluid goggles the large fonts are easy to read at any depth.
The Xen decompression algorithm was developed by former world record holder and current holder of the North American CWT title of 104 meters Eric Fattah. The Xen decompression algorithm took 12 years to develop and incorporates both the results of extensive self-experimentation as well as extensive DCS history from other top freedivers in the world. The Xen also includes three levels of conservatism, to allow for different decompression requirements based on individual preference and susceptibility to DCS.
The Freediving Xen samples and logs data 4 times per second, allowing every swimming stroke to be clearly visible in depth graphs, not only in no-fins diving, but even when diving with a monofin. The optional Xen PC interface works for both PC and Mac computers.
Anyone curious about the Xen or its decompression calculations can download a free, fully functional PC simulator which operates exactly like a real freediving Xen; allowing you to simulate any dive schedule and check to see what the computer displays. The simulator is available for download here:
Liquivision : Freediving : Xen Simulator
You can read more about the Xen here:
Liquivision : Freediving : Xen