Mercury - Floating Prop Wrench Propeller Tools Composite Floating Design 859046M3. Overview. There's a certain calm that settles in when you know your gear won't let you down - the kind of confidence that keeps a day on the water feeling easy, even when plans change. That's exactly why this Mercury Marine part earns a permanent spot in so many onboard tool kits. The first time you swap a prop while drifting in a light chop and watch this wrench float instead of sinking out of reach, you'll under