摘要：This paper deals with the problem of obtaining the number of ship collisions in waterways crossing situations. The main facts causing collision will be defined as well mathematic model of obtaining the potential number of ship collision candidates (unless any manoeuvring action is undertaken). All potential factors contributing ship collision in waterways crossing situations are also dealt with. Actually, there are positions with for frequent crossing courses so this area will be the base calculating ship collisions. When two waterways cross, the first dangerous situation is course-crossing situation and it will be analyzed first. Other specific situations are overtaking and head
关键词：Crossing waterways; potential number of ship collision candidates; real number of ship collisions; probability of collision; causation probability; course crossing situation; overtaking; head-on situation
