耐水

1. Origins, structure, and basic meaning

• Structure: 耐水(たいすい) combines 耐, indicating resistance, with 水, meaning water. The whole word means resistance to water.
• Basic usage: It combines with nouns for product specifications or performance, as in 耐水仕様 and 耐水性能.

2. Common pitfalls and similar expressions

• The limits of resistance
  • 耐水 alone does not specify the water pressure or duration a product can withstand. The watch example's suitability for rainy days does not guarantee suitability for every underwater use.
• Concession with でも
  • 耐水性能のある靴でも introduces a qualification: water resistance does not remove every concern. The following 長時間水に浸すのは避けたい expresses the speaker's judgment that they would prefer to avoid prolonged immersion.