Mercury - Quicksilver Thunderbolt Propeller High-Performance Prop Series High-Polished Stainless Steel QS5007X. Overview. When you lean into the throttle and the boat responds without hesitation, you know your setup is right. The Quicksilver Thunderbolt propeller is built for those moments - when power matters and control can't be an afterthought. It's a prop you trust to stay composed at speed, bite clean in rough water, and carry the load without feeling strained. From long offshore runs to wi