Mercury - Cowl Seal Verado Series Marine-Grade Polymer 8M0111178. Overview. Any seasoned boater knows that a good outboard doesn't just run well - it feels tight, quiet, and composed. A lot of that confidence comes from the small components you rarely think about, like the cowl seal that keeps everything underneath protected and secure. When your cowl fits snug and shuts clean, there's a reassuring sense of order that sets the tone for the whole day on the water. The Mercury 8M0111178 Cowl Seal