Engine Parts & Service - Exhaust Hose

A marine wet exhaust hose is a flexible tube designed to carry a mixture of engine exhaust gases and cooling water away from a boat's engine and out through the hull. Wet exhaust systems use water injection to cool and quiet the exhaust, making this hose a critical safety and performance component on most recreational and commercial vessels.

Marine exhaust hose is designed for boat owners, marine mechanics, and DIY boaters who need to replace, repair, or upgrade their vessel's wet exhaust system. Anyone operating an inboard or stern-drive engine that uses a water-cooled exhaust system will need the correct exhaust hose to safely route gases and cooling water overboard.

Start by measuring the inside diameter of your existing exhaust hose or the outlet on your engine's exhaust manifold or muffler, then match that measurement to the hose you purchase. Using the wrong diameter can cause exhaust backpressure, poor engine performance, or dangerous gas leaks, so an exact fit is essential.

A wet exhaust hose is built to handle a combination of hot exhaust gases and injected cooling water, while a dry exhaust hose carries only high-temperature gases with no water cooling involved. Wet exhaust hose is the more common choice for recreational boats because the water injection significantly lowers exhaust temperatures and reduces noise.

Yes, some multipurpose marine hose products in the exhaust hose category are rated for multiple uses beyond exhaust routing, including water intake, bilge, and general fluid transfer applications. Always check the specific product's rating and intended use before installing hose in any application other than exhaust to ensure it meets safety requirements.

Silicone exhaust hose generally handles higher temperatures and resists degradation from heat, ozone, and UV exposure better than standard rubber exhaust hose, making silicone a preferred choice for demanding marine exhaust applications. Silicone hose also tends to stay flexible over time, which reduces cracking and the risk of exhaust leaks in the bilge.

Start by cutting the exhaust hose to the correct length, then slide it firmly over the exhaust fitting or connector until it seats fully, and secure each end with the appropriate marine-grade hose clamps. Double-clamping each connection is a widely recommended best practice to prevent exhaust gases from leaking into the bilge, which can be a serious safety hazard.

Marine exhaust hose should be visually inspected at least once per season for signs of cracking, softening, blistering, or odor, and most marine safety guidelines recommend replacing exhaust hose every five to seven years regardless of visible condition. Heat and moisture cycles cause hose materials to degrade internally over time even when the outside looks acceptable.

Marine exhaust hoses are commonly made from silicone or reinforced rubber compounds, with silicone being popular for high-heat wet exhaust applications and fiberglass used for rigid connector sections where a firm, heat-resistant fitting is needed. The material choice affects temperature rating, flexibility, and long-term durability, so matching the material to your specific exhaust system is important.

Marine exhaust hose should be stored in a cool, dry location away from direct sunlight, ozone sources like electric motors, and petroleum-based products that can degrade hose materials over time. Coiling hose loosely rather than bending it sharply helps preserve its shape and prevents premature cracking before installation.