Was curious about your comment and my understanding of the Ultra's capabilities. I do understand the difference between "water resistance" and "waterproof" as atmospheric pressure vs. water depth. But for some reason I still was under the impression the watch could dive down to 100m. Maybe I heard someone misspeak? So - went to find the Oceanic World Wide write up on their Oceanic+ dive computer app. Found it here:
www.oceanicworldwide.com
And what did I find?
- Depth – This is your actual depth during the dive displayed in feet or meters in a large, easy-to-read format. The maximum operational depth of the hardware is 130 feet (40 meters). However, the depth could be even less with enriched gas mixtures."
With that said - the chamber the guy used was a water chamber designed to test watch manufacturer waterproof claims. The Ultra did handle 50m rather well. Perhaps "certified" equipment needs to be capable of going deeper to increase ability to handle margins of error?
On diving - I'm not certified so can't speak with authority here but even if you do have a dive computer, don't you still take manual gauges as backup? Part of the certification is knowing how - or the theory - of diving to depths requiring decompression stages, right? So even if you do go with many people, you still have a way out - er up - yourself.