Vector charts made up of layers which can be displayed selectively. Each point on the chart is digitally mapped, allowing information to be used in a more detailed way, such as clicking on a feature to display its information. Vector charts have the advantage of being “interactive”. For instance, the operator can pre-set the vessel draught and a 1/2 mile exclusion zone. At any time when the vessel is within a 1/2 mile of an area of shallow water, an alarm activates. Chart data can be shared with other equipment such as arpa and radar. There are various chart formats. Hydrographic offices are responsible for the production and accuracy of the ENC material.