45 Colt brass redux

I've seen some brands of duct tape start to peel in a few weeks time, and it wasn't under water, just exposed to the elemenets. Your life, your boat. Do what you want.

As far as Myth Busters, they do make mistakes.

Myth Busters is based about 30 miles from where I live. I take art welding at times at the local JC. The instructor hates MB. Bad welding practice and safety, and the tattooed lady that welds for them at times, used to work for him in private industry. Was not the best welder he had from the feelings I get. Different grades of Duct tape. Originally was aluminized medical adhesive tape to seal ammo cans. Friend worked at Anchorage airport when a Japan Airways 747 slid off the icy runway and cracked the tail assembly loose. Boeing showed up with 3' wide, 1/8" thick duct tape and taped the tail together, removed all the seats and the test pilot flew it back to Seattle. And the duct tape for leading edges of helicopter blades that is referred to as 125 mph tape.

None of which you are likely to have on a boat when you need it! ;)