Years of development and painstaking effort to design a clean, quiet and foolproof exhaust system have resulted in the system found on most of today’s Nordhavns. In lieu of a conventional wet exhaust, all of the single-engine Nordhavns are designed with a dry exhaust system and recessed keel coolers. This is a closed system where the engine's coolant supply is circulated through a captive series of tubes recessed in the vessel's hull. And, even though it meant the addition of more under water keel coolers, some twin-engine Nordhavns have been successfully designed using dry exhaust systems.
No salt water enters the ship, and the engine-mounted raw water pump, heat exchanger, anti-siphon valves and seawater exhaust are eliminated. With no strainers to clog, no impellers to break and no belts to fail, reliability is greatly increased. Designed with special noise attenuators and installed as an isolated, free-floating system, gas and noise are virtually eliminated. The exhaust goes largely unnoticed by all as it is vented far above the top deck.