Very windy but calm sea - why ?

[mcphailan]

We left our chalet on holiday with a high wind blowing around us, thinking no way would the sea be suitable for our young daughter.  Passed the beach and noticed the sea calmer than ever!  In fact, like a swimming pool.  What are the physics behind this?

[Tim Baxter]

Waves are generally created hundreds, even thousands, of miles out to sea by storms/high winds.  It is the swell from this reaching the shore and being forced more vertically by the sea floor approach to the beach which causes waves.  So even if you have local high winds they are not suffciently strong enough to cause more than ripples.

[Mortartube]

Somtimes winds will veer or back so that they blow offshore and actually flatten down waves caused by onshore winds that prevailed a few hours earlier. There are many variables that can cause waves or calm conditions. i.e wind against tide etc, also high cliffs can shield the sea below from the effects of an offshore wind for some miles out to sea. Heavy rain can also flatten down waves.

[mcphailan]

Many thanks, both answers fascinating.  By the way, it was a beautiful sunny day (and very windy)!  There were calm days when we had plenty of waves.....but Tim's answer caters for this.