A partial propulsion failure occurring on a commercial vessel can result in significant injury and damage when the movement of the vessel is unchecked and an allision or collision occurs. In some circumstances a significant amount of hull damage can occur at very slow speeds, while in others, multiple fatalities may occur. Owners and operators, and those responsible for vessel maintenance, specifically steerage and propulsion systems may find the following information useful and recognize the need to examine their own vessel's equipment and maintenance systems. Although the following speaks to a specific propulsion system, the noted lessons are useful for any type. The vessel was equipped with cycloidal drive units fore and aft.