Mercury - Tow N Stow Outboard Cover 75-115 Horsepower FourStroke Series Polysoft II Fabric 8M0221491. Overview. There's a quiet comfort that comes from knowing your engine is protected the moment you step away from the boat. Whether you're trailering down a long stretch of highway or tying up after a full day on the water, the last thing you want is road dust, salt spray, or harsh sun taking a toll on your outboard. This Tow N Stow cover gives you that peace of mind. Slide it over your engine, p