But even with all these, success is far from assured. This is because the ocean floor is littered with artillery shell fragments and other metallic junk that create numerous obstacles to searching, so it is still necessary to have divers go over the ocean floor using the naked eye and a fine tooth comb.
但光憑這些設備也不打包票，因為海床上常會有些如破砲彈等金屬殘骸，增加許多搜尋的阻力，因此由有經驗的潛水人員深入海底，以肉眼地毯式搜尋，成了必要做法。