Inshore Traffic Zone

An inshore traffic zone, ITZ, is the charted area between the landward boundary of a traffic separation scheme and the adjacent coast, the band kept clear of through traffic. Under COLREGs Rule 10(d) a vessel must not use it when she can safely use the appropriate lane of the adjacent scheme. The exceptions are vessels under 20 meters, sailing vessels, and vessels engaged in fishing, plus any vessel en route to or from a port, offshore installation, or pilot station within the zone, or one avoiding immediate danger. The ITZ is not part of the separation scheme, so the lane-following duties of Rule 10(b) do not apply inside it, though the ordinary steering and sailing rules still do.