To Summarize Silmaril - are you nuts?
On the water is clearly so far safer than on land. On the water you just worry if the safety
line will hold. The water
line is the fulcrum to the balast. On land the balast will kill you. A stiff breeze might be all it takes. A 170 pound human up 50 ft makes for a huge of Newtonian moment. This is late 17th cenntury mathematics.
You might do well to purchase a few sky hooks.