Go for it! It sounds like a good plan just watch the weather and take the advice presented so far on this thread.
I just turned 53 and have sailed Bimini and The Dry Tortugas after double knee replacements and 3 major back surgeries. (the last one put 3 screws and a metal band at L3,4,5) I still have my health and am looking forward to much more Blue Water sailing now that the kids are gone. (YEA!)
Remember the old song "I'm much too young to be this damn old" and keep on sailin'. I still race every chance I get (inland lakes around Dallas) as it keeps you moving and thinking.
50 is only half life.
Opportunity is missed by most people because it is dressed in overalls and looks like work.