透とう視し度ど

noun

horizontal transparency; water clarity; visibility (diving)

Technical term used in environmental science and diving to describe how far one can see horizontally through water.

• この湖みずうみの透とう視し度どは約やく10メートルです。

  The horizontal transparency of this lake is about 10 meters.

• ダイビング前まえに透とう視し度どを確かく認にんした。

  I checked the visibility before diving.