Interestingly, risk assessments (properly, hazard identification and risk assessment - these are two distinct processes) are not a routine part of my present job, which is more concerned with dealing with the aftermath...

That said, yes, hazard and risk assessment of single-handed offshore sailing is entirely possible, though there is a paucity of data in some areas. In its most basic form, it's something that doesn't require a professional touch, and can be taught in about half an hour.

I must point out that, notwithstanding my earlier remarks, I do fully recognise the fulfillment to be gained from single-handing...