Learn to swim.  Every year people drown because they fell in a river, off a boat, or into a pool and didn’t know how to keep themselves afloat.  Everyone should at least know the basics. 

Never swim alone no matter how strong a swimmer you are. If you get hurt, cramp up or are caught in a current there will be no one around to help you out.

Learn CPR (CardioPulmonary Resucitation). If you and your friends all know CPR there’s a good chance that you will be able to take better care of each other if you ever do get in trouble.  CPR is a first aid technique that allows a person to help the victim of an accident continue to breathe while they are unconscious and waiting for professional help to arrive.  Most communities have a variety of classes available through the Red Cross or American Heart Association.

Night swimming (except in lighted areas) is very dangerous.  It may seem edgy and fun, but unless you are in a lighted pool, swimming at night can be just as dangerous as swimming alone.  You won’t be able to see what’s in the water, like shallow rocks or logs.  It is also very easy to lose track of how far you are from shore and where your friends are.

Never swim during a thunder storm or in other severe weather conditions.  Lightning is attracted to water because it is a good conductor of electricity (the electricity can move right through water without too much trouble).  If a lake or pool is struck, the energy from the lightning passes through everything in the water- including your body!  Heavy rain, hail, high winds, etc. can all cause water to be choppy and dangerous. 

If swimming at a beach, make sure you are aware of any hazardous tides or undercurrents.  Check for signs or ask a lifeguard if there are any tidal changes or undercurrents that you need to be careful with.  These forces of water can suck even the strongest swimmers away from land within just a few minutes. 

Never swim if you are very tired.  Many people think of swimming as a relaxing activity, but swimming (real swimming- not just soaking on the stairs of a pool) can be a pretty intense cardio workout.  It uses almost all the muscles in your body!  If you try to take a swim when you are already tired you may find yourself far from shore and out of energy.  Rest up then hit the waves.

Never swim when you are feeling cold.  When you get out of the water your body being wet will cool you down more, even if the water is warm.  It’s not worth it to get sick just for a quick dip.
  
Don’t swim for a ½ hour after eating.  Everyone has probably heard this a million times but do you know why?  When you’ve eaten a big meal, your body concentrates a lot of its energy on the process of digesting that food in your stomach.  If you try to exert yourself while that process is still going on your body may try to signal you to stop.  A common signal? CRAMPS.  A bad cramp while you’re running means you have to sit down for awhile but a bad cramp while you are swimming could leave you helpless out in the deep water.  Play it safe and let your body do its job first, then go swimming.

Always wear sunscreen when swimming outdoors.  Water is deceptively cool on the skin.  You may not get that super hot burning feeling you would otherwise get from the sun.  The truth is, though, that the sun’s rays are intensified by reflecting off the water and hitting your body at all different angles.  Apply the sunscreen liberally and often so that you don’t end up red and sore.

Wear your PFD.  PFD means “Personal Flotation Device” or maybe you know them as lifejackets.  Even if you are an Olympic swimmer, when you’re out on a boat you should be wearing one.  Boating accidents are more likely to involve your being hit by something or injured in some way.  You need to have something to keep you safely floating above water even if you go unconscious.