Like bipolar disorder there should be two classifcations for the condition we know as 'did not finish'.
DNF 1 might be for failing to finish due to circumstances beyond the swimmers control. This diagnosis would apply to weather conditions that threaten the safety of swimmers and crew or freak currents where the math doesn't work - the currents are just running harder, longer and faster than any swimmer can swim.
In my Diagnostic and Statistical Manual of Sporting Disorders, DNF 2 would be an altogether harsher diagnosis. It would be reserved for failing to finish due to matters for which the swimmer is ultimately responsible - insufficient training, poor diet when training and competing, and perhaps more controversially, physical and mental weakness.
When it comes to swimming I have neither condition. I have finished all marathons swims I have undertaken. However, as in matters of love, reputation, power, and money, the more you have the more you fear loss, and so it is with achievements.
Yesterday, 10 days out from my USA Catalina Channel swim, a leading Sydney sports physician told me without reservation I would not finish my swim due to a last minute shoulder impingement. A second opinion today from an equally experienced and well regarded sports physician says with a week of gentle exercises, heavy strapping, some cortisone and a slight modification to my stroke he's mildly optimistic I can make it.
My body is my responsibility. At my age I needed more gym work. I was warned. I hate gyms. I didn't do it and now I'm facing full blown DNF 2.
I can do without another disorder so I'm going with Dr. Mildly Optimistic over Dr. Unreserved Failure. I will post my tracker details in the next few days so you can see who was right.