To extend the search, especially for the wreck of the missing boat, a naw hydrographic vessel employed a proton magnetometer -- a powerful metal detector -- and side-scan sonar, which gives three-dimensional readings.

• 为了扩大搜寻，特别是搜索失踪船只的残骸，一艘海军水道测量船采用了质子地磁仪，一种功率强大的金属探测器和侧扫描声纳。 侧扫描声纳可以给出三维读数。