rip currents (離岸流) についての、とても良いブログ記事を見つけたので、引用です。これは、カリフォルニアでしょうね。この離岸流のサイン、ミシガン湖だけではなくて、全米で同じサインなのですね。英語ですが、頑張って読んで、波にさらわれて溺れないようにしましょう！
It’s beach season and my kids are getting braver with their newly acquired swimming skills but it also made me realize that with their increased water skills and confidence comes increased risks as they venture further into the water and so we’ve been on a but of a mission to learn more about the importance of learning to “read” the ocean in particular the often misnamed rip current (not rip tide).
Why Rip Currents are Dangerous
Rip currents are the leading surf hazard for all beach goers. They are particularly dangerous for weaker or non-swimmers. Rip current speeds are surprisingly fast, typically 1-2 feet per second however, speeds as high as 8 feet per second have been measured–this is faster than Usain Bolt can sprint! So beware rip currents can sweep even the strongest swimmer out to sea.
According to the National Oceanic and Atmospheric Administration (NOAA) Over 100 drownings…
View original post 387 more words