Many builders have used the hose clamp method that Ben mentions over the years, and truth be told, it works OK. The stainless is fairly inert galvanically so it won't rust or corrode. It looks funky, but as long as the clamp is tight, it will hold the 8 AWG wire in place firmly against the piece of metal that is to be connected. As for the copper strap shown above I say the stainless clamp is a better choice. The clamp above is going to actually induce some corrosion on a bronze thru-hull fitting, and really doesn't provide as infinite an adjustment as the stainless steel hose clamp.