I use the standard Mercury tethers with an extention that velcro's to my wrist. The Mercury tethers are too short for me and get in the way while turning.

You can see it on my right hand in this pic. The extention I got is for Sea Doo racing and can be bought at Boat USA, West Marine, or any Sea Doo/Yamaha/Jet Ski dealer.

I wear mine on my shorts loop.

Speaking of aftermarket kill switches. I bought this one, and tore half my wiring apart trying to figure where to mount it. I was tracing some wires from the old radio, when I found the factory kill switch already mounted in the boat.

Btw, I installed one of those aftermarket switches on my Formula 20 Sc. I found it would fit perfectly in the hole where the old ciggarette lighter was, so I mounted it there, and didn't have to drill any holes.

i saw the sea choice ones they look like a pos compared to the mercs

Yeah, they ain't much to look at, but they WILL kill your engine, which is what it's all about.

Anybody mount a relay to handle both engines with one switch and lanyard?

shouldn't you be looking the OTHER way....?

It's no fun looking that way anymore. Besides, SBRT is behind me.

My '88 Formula didn't come with one. Been looking around and the price for a Mrec switch is expensive for what it is till I saw what Fred, Trick Marine, was selling them for. Ordered one right away.
THANKS FRED!