Amen to that. What most concerns me when I solo is not an emergency at depth (though that does concern me - a lot), but having a reasonable likelihood of someone seeing your signal if you are in distress after you make it to the surface. Von Maier puts it well in his book "Solo Diving", that diving conservatively, being in proper physical shape, knowing your limits, and having a completely redundant air supply are all keys to responsible solo diving. A scenario which gives me pause would be doing what I call "Isolated" diving (my term, maybe there is a better one out there somewhere), where the solo diver is out in the middle of nowhere in an isolated location and after doing an emergency ascent is adrift but unable to make it to shore (maybe a cramp, injury or loss of a fin), with a current carrying them out to sea. At that point, deploying a safety sausage or some other signal and hoping someone sees it is your only hope, which is a risk I find unacceptable. That is why when I solo, it is in a location with lots of other folks around (Lake Rawlings VA or La Jolla, CA for example), and preferably a lifeguard shack to check in and out with. In that situation, I feel comfortable that if I need assistance on the surface, someone will see my signal and be able to assist. With proper risk management and extremely conservative dive profiles I never plan on being in that situation, but it is nice to have a plan.