On 22 July 2015 the US Coast Guard issued a Navigation and Vessel Inspection Circular (NVIC) clarifying the requirements for reporting marine casualties in US navigable waters and the Exclusive Economic Zone (EEZ). Under US regulations, "marine casualties" are broadly defined and include any occurrence involving a vessel that results in injury or loss of life, grounding or stranding, collision, explosion, fire, loss or reduction of electrical power, propulsion or steering capabilities, any circumstance affecting the vessel's seaworthiness, and any incident involving significant harm to the environment. The NVIC provides a detailed outline of Coast Guard policy and interpretive guidance for each category of reportable marine casualty. For example, "loss of main propulsion, primary steering or any associated component" not only includes occurrences where the applicable component or system unexpectedly fails, but also situations where the component or system is intentionally shut down as a preventive measure. Pain or sickness caused by an illness (such as cold and flu) or pre-existing medical condition (such as heart attack or stroke) does not fall within the scope of the reporting requirements for "injuries" unless it results in physical injury requiring professional medical treatment beyond first aid. "Significant harm to the environment" means discharges of oil that violate water quality standards or cause a sheen on the water surface, or discharges of hazardous substances in equal to or in excess of the reportable quantities under federal regulations. Although some marine casualties may not meet the criteria for reporting, vessel owners and operators must consider whether such incidents must nevertheless be reported as "hazardous conditions," such as falls overboard that do not result in injury or death but may create a hazardous condition when the vessel maneuvers to recover the individual in a congested waterway. Another example is a "bump and go" grounding where