Shipwaves can have harmful effects on people who are using riverside and cause bank erosion, bank structures destruction in restricted waterways. The wave field near a vessel is consisted of a combination of a primary and secondary wave system in a shallow or restricted waterway. The water level depression(squat) and return current beside the hull are called the primary wave system. The secondary wave system, that is the wave height originates from a local disturbance point such as the bow of the ship. This study aims at investigating the characteristics of the wave field around a vessel in a restricted water in relation to navigation experimentally and theoretically. The return current and squat with a correction factor can be newly evaluated and the almost same high-sized wave heights take place on the whole waterway in a restricted water without regard to the distance from the sailing line.

Shipwaves am have harmful effects on ships working on the sea, in a harbour or navigational channel and caused beach erosion, seawall destruction. This study aims to investigate describe the characteristics of the wave pattern generated by an individual model ship tested at different velocities and hull forms for a given water depth and to investigate the variations at a given distance from the sailing line under the same conditions. As a result, the angles a's by model ship tests are smaller than those by real ship ones. Wave heights decreases with an increasing the mid-ship cross sectional area As. The maximum wave height and period increase rapidly in the subcritical speed, and beyond the critical speed the height and period decrease with increasing depth Froude number. And the period keeps constant with the distance from the sailing line.

항주파는 해안침식, 호안 결괴, 하역곤란 및 어선 등 소형선박의 동요를 발생시키며, 최근에는 고속으로 항행하는 수상오토바이, 모터보트 및 여객선 등이 수영객, 낚시꾼 및 어로작업중인 어민에게 위협이 되고 있다. 본 연구에서는 실험 및 이론적으로 항주파고의 전파특성을 검토하였으며 상대수심이 얕은 수역에서 발생한 항주파가 천해역으로 전파하는 경우 파고증가율이 커지며, 수심이 얕을수록 유속이 느린 흐름이 존재하여도 파가 진행하지 못함을 알 수 있다.