Sharks in Thailand

Each morning after breakfast Moon and I would take up our position in the lounge chairs, a few yards from the water.  I would swim out to a small rocky island...maybe 300-400 yards away.  I'd snorkel for awhile, then swim back.  On the last monring I walked to the beach and noticed the water was very cloudy.  When I dove in the water was so stirred up that I could barely see the fingers of my outstretched arm.  But I swam out...lifting my head on occasion  to mak sure my direction was straight.  The rock was a couple feet away....I almost ran into it.  I was too cloudy to snorkel.  So I turn turned around and headed back.  On the way in I started thinking about sharks and how this might be a perfect time for one of those Great Whites to sneek up on me and chew off one of my limbs......ouch.   Why these thoughts on the last day I'm not sure but I had a premonition.  The first thing that sharks do is bump their prey before  they attack.  And just about then and only 50 yards from shore I felt a pretty good bump on my right leg....I immediately stopped, tensed up, and lifted my head out of the water to locate a fin or the telltale sign of a water disturbance.  There was nothing....so I took a deep breath and put my head into the water....looking around, still trying to locate my attacker...they say if you strike back at a shark it might scare it away....so I was ready with all my strength.....then just beneath me....there it was...a sand covered rock I had inadvertantly run into while swimming to the beach.....to say I was relieved is an understatment...not sure how I could feel beads of sweat pop out on my forehead while already in the water     but I did....and while the danger was completelyl gone....I still took off for the shore pretty quickly.