Free Diving Progress Training (Safety Device)

A pulse oxymeter is great training device but should never be used as a failsafe or 'black-out alarm'. I just know if I was training that hard in the water, my safety needs to be watching me like a hawk and not much more than arms length away. He/she shouldn't need an alarm to know that I am out.

HOWEVER, a pulse oxymeter that could be worn in the water and just used for training and benchmarking would be super useful. I've worn a fingertip model in the water with a clear plastic bag duct taped around my hand. I would love to train with one all the time but that set-up isn't practical. One that would work at real depth (like in the ocean) would be even better.

Depth freedivers often wear their dive computer around their neck or in their hood so they can hear their depth alarms.

Perhaps you can have a small earpiece/ temple design to log: depth, time, dive number, heart rate, SAO2%, and have some set able alarms?

I think the Instabeat device already has great potential. What you need to obtain is their source-code and access, and expend on their design, replacing the light arm interface with adjustable beep sounds for instance.

A BO alarm would not work, or be counter productive. For instance: when set too early people continue, when set to late people respond to late and or are to far from the surface. When they do set it correctly they start to rely on the device and do not learn to develop their inner sense of their limits, making their safety totally dependent on the reliability of the device.

As a log and alarm I think it gives freedivers great data to analyse and great info to complete the most challenging dives.

So a little rounded box, with watch battery, solid locking compartment for battery and USB interface, and band guides to attach it to a strap (Or mask strap) going around the head, holding the device in place.

A rough sketch:
2 modes: standby (clock), dive mode (when wet).
Logs: 4x / second: Depth, time, HR, SAO2.
8 set able alarms: To each one can set volume, pitch, tune so as help to distinguish what alarm goes off. The alarms could be set to Time, Depth, HR and SAO2.
Interfaces: SAO2% sensor, Depth sensor, sound, USB, NFC (to connect with mobile phone)
Memory: Enough for a week, 7 x 2 hours, basically recording 4 numbers (time, depth, hr, SAO2) x 4 a second. Plus the set alarms, and software and interface for phone and computer. (Micro USB?)
Power: USB and user replaceable CR 2032 battery.

This would be an extremely useful device, suitable for more sports then just freediving.

Love, Courage and Water,

kars

ps:
One could still set various alarms to SAO2 on this device, hence it could help to alert the diver to come up in time, however I suggest not to sell it as a safety device, just imagine the possible accidents and claims that you can expect from misuse, dumb use, equipment failure etc.