Who made up these requirements? Did you read it in a book. This is like the manufacturers and instructors taking over the sidemount forum now telling everyone they need to buy XYZ harness and take 123 course to do that activity. But let's look at your list.
Redundant air as a solution to entanglement? Who teaches that because I've never heard it. Your "reserve" gas used for solving problems is factored into a gas plan and usually revolves around the size of primary cylinder chosen. Truth is, if you can't get out of an entanglement within the time allotted by a conservative primary gas plan, you probably won't. If someone feels that volume is not enough they need to revisit their reserve calculations, not add another piece of gear to compensate.
As for murphy's law. We usually plan for one failure, not sixteen, after all Murphy knows no limits. Why not have three redundant air sources in case you burn through one and forgot to fill the other.. oh wait make it four, that third one is filled with 100% helium.
A redundant air supply is used when a primary gas failure makes ascent problematic. If you are within CESA depth, and are competent in that skill, a redundant air source is
not required. You would make a direct ascent. To advocate solo diving and not emphasize that ability (and the skill required) is sub optimal IMO. The surface is a great and easily attained solution to almost any problem - learn to use it. This also goes hand in hand with not bumping up against or violating NDL's and does not include boat traffic or other impediments. In those cases a redundant air source, even at shallow depths, may be required. Those concepts would fall under:
- Plan a dive,
- choose the right equipment,
- maintain situational awareness throughout the dive,
- avoid hazards,
- self rescue,
- and know ones limits.
However, I do see a problem when solo diving becomes a course to be taught instead of an activity. Knowing your limits and developing skill are very individual ideas, not easily taught. An instructor cannot "know someone else's limits" once they leave the course or "develop skill" for them. One can indicate the way to do it but ultimately, that is up to the individual. Instead, overarching bandaids like total redundancy and diving thirds are taught as a sort of "catch all" contingency. That speaks to the weakness of teaching solo diving to the masses though, not the dedicated solo diver.
A redundant cutting tool is actually one thing I do believe in, mainly because under stress I think it's pretty easy to drop one. It's why I have a wrist loop of bungee through mine. Before adding the second tool, have you remedied that issue with the first?
Redundant mask?
Redundant computer?
Redundant compass?
Redundant Snorkel?
Not for a 30' dive, unless specific conditions indicate otherwise.
I mean, when you make a blanket statement like you need complete redundancy I am curious where that starts and where that ends and whether people actually think about what that means.
