While shopping for possible hurricane provisions yesterday, a recent arrival on a Newick tri we bumped into by the dairy case asked me about climbing gear for climbing the mast and what I used and it occurred to me that some Boat Bits readers might have an interest...
These days I use a pair of Petzl ascenders (I've always liked Petzl products) and they make a lot of sense for going up a mast. They also have a variety of uses around a boat as when you get down to it they are really just a portable clam cleat and, if you think of them in that light, they become a tool with great possibilities.
Using ascenders for climbing a mast is quite simple but I'd seriously suggest spending a few hours at your local climbing wall to learn how and to get comfortable with the process and what it entails. When you graduate to using ascenders to climb a mast, do make sure you sort out a top rope with an extra halyard and have somebody you trust to do the belaying.
If I were to buy a pair of ascenders for the boat today, I'd take a long hard look at a very simple, elegant, and inexpensive ascender that Petzl has called the Tibloc.

Just a heads up, but EMS

Listening to some more Don Nix
So it goes...