Well here is a thought for you to consider. I do dive solo from time to time usually in support to local law enforcement but then there are surface tenders and divers ready to enter the water and guidelines that are followed. I dive for the IUCRR, a team effort always (IUCRR=International Underwater Cave Rescue and Recovery) by the way there are never any rescues. I have certification to instruct SOLO diving but I have yet to ever issue a cert card for this. Many have asked me for it and after questioning them and in some cases making a dive with them I simply tell them they are not ready to dive SOLO. It is generally my experience that they don't have the basic O/W skills developed yet, they don't have the basic knowledge or habits of correct dive planning and preparation procedures, they are not willing to purchase the required equipment for SOLO diving - hence their commitment and their desire for this form of diving, and usually I don't feel that they have the acceptable ATTITUDE to truely and Safely SOLO dive. I will not look at any diver with less than 100 logged dives minimum for this certification (SDI Standard). Even with a proof of 100 logged dives if all of what they were doing was just a continuation of poorly learned and practiced skills they would not have the basic OW skills required. Divers that I feel may have the required skills and knowledge and still don't have the proof of 100 logged dives I don't accept for SOLO certification training because I feel that failure to keep a current log book (written or computer download) is a failure of attitude in diving. On a side note I believe that the log book is often one of the most overlooked and ignored tools that a diver has to help improve themselves. Now you might say that I am arogant in this and very subjective. I am more likely to hand a diver a wreck, ice, cavern or cave certification than I am a SOLO card. And I am not so quick to hand those out. As far as SOLO diving within a overhead environment I do not support nor condem it I leave it as the indivduals right to make that choice. I strongly suggest to any diver whom chooses to dive SOLO siting reasons of bad buddies skills, buddy team responsibilties and awareness, couldn't find a buddy and any other reason for not wanting a buddy to dive with should look at themselves and place a honest judgement as to who the poor buddy actually is.
You want to SOLO dive consider these points because if you fail to plan or react correctly there is only one outcome:
Depth and Dependency of self abilities
Environment and Equipment requirements
Air (gas) and Awareness /Attitude
Time and Training of skills
Health and Habits of consistency