Dan, I have no problems with people wanting to push limits, but when it involves putting others lives at risk for their personal gain or whatever, then I am sorry but I don't think that is what the rescue crews are there for, although as professionals they would never say no. They are there for the everyday stuff, accidents, unforseen incidents e.t.c. NOT people who are deliberately pushing limits, because that is frought with danger, otherwise it would not be worth doing.
All I am saying is, if you want to go to extremes (beyond what normal people would do), then take the appropriate measures e.g have a backup rescue team, or insure yourself in some way to pay for any such rescue by people on standby that may be required. Not drag some poor unsuspecting buggers out of bed at a moments notice and send them in a chopper 200 miles out to sea. Why on earth should others have to risk their lives because someone wants to prove a point, sensless and could be construed as selfish if you ask me.
I agree it is good to push boundaries, and exciting, but not drag some other people into your danger that you have deliberately caused (deliberate, because you know it is dangerous, otherwise it would not be a challenge would it?)
With your trip round the IOW, I would hope that you have safety boats on standby, or people to assist, although it is not quite the same as heading off into oblivion
Good luck with that anyway, sounds fun.