Mercury - 200-Amp Fuse Electrical Protection Series Marine-Grade Blue Fuse 8M0161644. Overview. If you've spent enough time around boats, you know that electrical protection isn't something you appreciate until the moment you need it. A fuse may look small and unassuming, but it stands between your engine and the kind of damage no boater ever wants to experience. That's why Mercury Marine part 8M0161644 carries so much quiet value. It's the kind of part you trust without even thinking about it -