It would be great from our point of view if the law had special rules for single-handers. It however does not.
Can you offer an example of what might be such a Special Rule?
Perhaps it's just me, but if someone is overly concerned about what current Maritime Law has to say about singlehanded voyaging, to the extent that it might actually impact their decision whether or not to do so, well... they're probably not cut out for such voyaging, to begin with...
For most singlehanders, I think the far more relevant concern is insurance... IMHO, Rule #1 for a solo passagemaker should be "Don't Sail a Boat You Can't Afford to Lose"... (grin)