What causes whirlpools in the water, like close to the coast. (As in Norway)

"Whirlpools occur when two opposing currents meet. They cause the water to spin round and round very rapidly. Huge whirlpools at sea are normally caused by powerful tides. The most famous whirlpool is the Maelstrom, which appears between two islands off the coast of Norway.Nov 5, 2012"

Source:

http://lmgtfy.com/?q=what+causes+coastal+whirlpools%3F

They are trans-dimensional portals created by aliens. 

Nice! Like in the movie "Interstellar"? I love that movie!

Thanks, DTT! I was watching this documentary about Norway. It was awesome. I did see those huge whirlpools!

#W., not quite. I was watching a documentary about a 6 day cruise on the coast of Norway. Such a beautiful country, if you like sailing, mountains, waterfalls, fish, and different cultures.

The most amazing part to me, as I love science, were the giant whirlpools. I have never seen such a sight, nor even heard of such a place. So it seemed magical. There was a Troll Island with real trolls as well. :-)