Well, we have managed to scare the dickens out of the OP which we did not mean to do.
My plans when going out are quite simple:
5 to 10 mph winds, go for it.
10 to 15 mph, watch conditions at the area where I plan to launch the boat and pay close attention to wind direction. If it looks bad, return home or select a better launch site. You will get wet out there.
15 to 20 mph, stay in protected rivers only, but watch tidal flow vs wind direction. Don't even think about going out on open water, as the transition from river to ocean will be bad. Even a river can be rough if the water flow and wind oppose each other.
20 to 25 mph, go do something else and forget boating.
The whole thing boils down to using common sense and your eyes.
As far as Chapman's book goes, it should be required reading for anyone contemplating going out on big waters. It is a standard reference book for mariners.