Ship’s safety requires continuous identification and assessment of the navigational situation. The assessment of own ship’s safety is often reduced to watching the estab-lished zones around the ship. The safety level is decreased when another object disturbs the established zones, which requires evaluating the risk and making adequate coun-termeasures. The situation when we have to maintain an adequate level of safety leads to another approach, i.e. it requires navigating the ship within an established zone (traffic separation scheme). In the paper different kinds of ship’s zones and their purpose are presented.