You know you missed the swim turn when

Good thing you caught it early!

I think the word you were looking for was "quiet".   *yep, I'm smarmy.*

Oooh! Me! Me!

Have you ever tried to stretch your toes really, really long?

I've also did the off-course number. I claim I was trying to swim to France.

Yep done that one.

Then again, I've also almost fallen asleep when doing laps.  I'm serious.  Last year, was my second year swimming and I did the swim early in the am (5:30).  It was during the warm up (a 400 or 500 I believe) when I realized that my eyes were closed and had been for at least 6-7 strokes.  Interestingly enough, I even bi-lateral breathed during this little "cat nap". 

Actually almost did it on the trainer once on a very early morning ride this past winter.  But I've never come close to it on the run.  The wife thinks I'm crazy that I almost fell asleep in water.  Exercising. 

A favorite local sprint that I've done several times is in the TN River.  You swim diagonally across/down the river and then diagonally back/down the river.  The problem is, there is a pretty good current in the river!  So if you aim for the buoy, the current will sweep you down river and when you finally close to the buoy you are down stream of it and have to swim back up river to get around the buoy.  You have to 'aim' way upstream of the bouy to account for the strong current. 

So to answer the OP, 'If you look up and see people swimming in the opposite direciton that means the current hase taken you down river and you are in trouble!'

~Mike