There are some valid points, I've been on many dives where I have often been paired up with somebody with less experience and then spend most of the dive watching them. To say Dive Buddies can be a safety number isn't always the case, I've had in experience who ignore your U/W signals, get lost, surface early, play with their U/W Nintendo ( sit on the bottom and just fiddle with dive computers) this is usually the ones with too much money and ego, plus not much divin experience.
Whenever there is a handful of experience divers in a dive club social group who want to dive together , there is a good chance they will be split to watch others ( inexperienced), so the question on diving solo is intereting , and agree with many on this particular, once below the surface the dive buddy system can break down leaving alot of people diving solo in a loose collective.
I've solo dived a number of times over the years, but like most divers when your in a dive club you get paired up.
Shallow water blackout and all sorts of diving nasties can be a concern along with equipment malfunction and weather hazards. If you risk assess your dive and you have identified all the potential hazards and reduced the risk with control measures as low as reasonable possible then what more can you do, but enjoy the dive. My rule of thumb which I use for
My safety ( personal) is not solo dive below open water certification depth limit eg. 18 meters max. This is my own diving rule.
I've been diving over 17 years and hold Open, Advanced, Rescue, Nitrox & Deep Diver qualifications. I'm planning to finish to Master Scuba Diver Level, can't see the need to do DIvemaster quals.
If all the scuba divers in this group are scattered and few perhapes we should organize a group Kayak Dive a few times per year over a weekend or something, I'm certain we could find a location we could centrally meet that we all agree with. Let me know what you think.