Open Water Swim Anxiety

For many triathletes, the swim is the aspect most foreign to them. Even for those with a swim background open water swimming is a different beast. Preparing and understanding this anxiety can help you to that PR.
First key is understanding the differences. In open water, there are no walls, no lane lines, no markers on the bottom to guide you. Often the water is more difficult to see the bottom. Water temps are less constant, and there may be "stuff" to encounter. Finally when it comes to a race, people actually will get in your lane. Races can also being in a number of manners, from beach start to in water start. Longer races can have loops where you exit the water which also changes the bodies physiology. Knowing these differences exist and practicing in them, allow a calming of anxiety through familarity.

Safety. The most important thing to remember is never swim alone. Also when in new areas swim with those that know and understand the waters. Knowledge of pilings, and jettys, will save your life. Water temps are much different than in pools. Wear a wetsuit. it will give you added buoyancy plus warmth. On race day, acclimate yourself to the water before the start. In addition to wetsuits, bathing caps increase both warmth and visibility. Ear plugs, prevent swimmers ear, and increase warmth, but can limit you ability to hear.
Sunscreen Remember that your neck is exposed in a wetsuit, and will burn. Do not apply sunscreen to areas that will be covered by your goggle, or your eyes will burn. When putting on a wetsuit, using a lubricant such as body glide or suit juice will allow for easy on and off, and prevent chafing caused by wetsuits.
Whether racing or practicing know your surroundings. Study water temps and tides, and currents, so you know what to expect before entering the water. Never attempt to finish a swim against the current. Realize that visual aides to distance can be tricky when outside, don't overdo it. Anticipate changes in weather, lightning can travel for over 5 miles. Prepare for marine life, vegetation, and have safety plans. Be conscious of others using the water, boaters, fishermen, and the like. Getting caught in a line, can be painful.
When in the water if you get anxious, roll on your back, look and the sky and float. Have a prepared safety stoke breast of back, to allow you to regain your composure.
Sighting. In open water, we tend to expend the greatest amount of energy by over swimming, by moving off course. Lengthening our stroke, and sighting ever few strokes allow for regular corrections.
So find a safe area, hopefully which mimics your races, and practice open water swimming with friends.