The simple bottom line is that you have to stop the RF from a transmitter from touching the mast. That means insulators. If the RF does get to the mast, standing rigging, etc., it's not going to do anything but short out, because the rig (had better be) is tied to ground.
The contraption on gam electronics page must be some kind of folded dipole or something, because it certainly isn't very long. Certainly not a quarter wave length at 40 meters, which is about where you'll be transmitting most of the time.
Norseman insulators aren't THAT expensive.
The other real option is to put on a multi-band HF antenna like the one from Shakespeare. Shakespeare Marine Antennas Specifications: Galaxy 5390 SSB
It's big, tall, and heavy, but they work.
Personally, I'd be leery of that folded dipole thingy.