A sea captain, ship's captain, captain, master, or shipmaster, is a high-grade licensed mariner in ultimate command of the merchant vessel. The captain is responsible for its safe and efficient operation, including: ship's seaworthiness, ship's safety and security conditions, cargo operations, navigation, crew management and ensuring that the vessel complies with local and international laws, as well as company and flag state policies. All persons on board, particularly during navigation, includ
1 âPrevalenceâ is the proportion of a population who have (or had) a specific characteristic in a given time period â in medicine, typically an illness, a condition, or a risk factor such as depression or smoking.
Incidence should not be confused with prevalence, which is the proportion of cases in the population at a given time rather than rate of occurrence of new cases.Thus, incidence conveys information about the risk of contracting the disease, whereas prevalence indicates how widespread the disease is.ncidence is usually more useful than prevalence in understanding the disease etiology: for example, if the incidence rate of a disease in a population increases, then there is a risk factor that promotes the incidence.