# Electromagnetic waves in water

**URL:** <https://boards.straightdope.com/t/electromagnetic-waves-in-water/70014>\
**Category:** Factual Questions\
**Created:** [June 24, 2001, 11:41pm UTC](https://boards.straightdope.com/t/electromagnetic-waves-in-water/70014 "2001-06-24T23:41:58Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Pushkin](https://avatars.discourse-cdn.com/v4/letter/p/ee59a6/32.png) [@Pushkin](https://boards.straightdope.com/u/Pushkin)\
**Post date:** [June 24, 2001, 11:41pm UTC](https://boards.straightdope.com/t/electromagnetic-waves-in-water/70014/1 "2001-06-24T23:41:58Z")

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Somewhere I read that submarines and ships use SONAR over radar not just because sound travels so much better under water but because radar can’t be used effectively under water. This apparently is because water restricts its effective range. I can see how effectively light is blocked out at greater depths so how does water affect radar so?

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**Author:** ![Punoqllads](https://avatars.discourse-cdn.com/v4/letter/p/d2c977/32.png) [@Punoqllads](https://boards.straightdope.com/u/Punoqllads)\
**Post date:** [June 25, 2001, 12:07am UTC](https://boards.straightdope.com/t/electromagnetic-waves-in-water/70014/2 "2001-06-25T00:07:26Z")

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Light and radar are both forms of electromagnetic radiation. The properties of water that allow it to absorb light are the same ones that allow it to absorb radar waves.