Ronald, maybe the nuclear plant at your beach is messing with the tides! wink
The theory is that because deeper water contains more water volume it causes a stronger flow of water,
but I think I'm swimming against the tide trying to convince you so I will go with the flow here. wink

Was kitesurfing this weekend at what is called the Sand Motor which has some really strong currents.

Here's a (very geeky) video explaining it: