Even in the apparently benign hobby of metal detecting, injuries can occur. In this article, I'd like to discuss some of the possible hazards and injuries that can occur, as well as some of their remedies.
Although metal detectors are made as light weight as possible by manufacturers, the body and coil of the detector can weigh several pounds. The constant swinging of the coil for long periods of time can cause not only fatigue, but injury to your elbow and shoulder. I myself have "tennis elbow" in the elbow of my swinging arm and feel pain there all of the time. If you metal detect in the water, you have the added resistance of the water against the control box as well as the coil. To avoid elbow and shoulder injuries, slow your swing down, alternate swinging the detector with your other arm, and take frequent breaks from detecting. If possible, mount your detector body on your hip or chest. This is especially true if you detect primarily in the water. Using a chest or hip mount drastically cuts down the weight you are swinging, as well as the water resistance when detecting in the water.
No mater where you are detecting, it's important to wear the appropriate footwear. If you are detecting on rough, irregular land, wearing a good pair of boots is recommended. Make sure that you have adequate ankle support in order to avoid ankle injuries. When metal detecting in the water, make sure that you wear water shoes, or at the very least some old tennis shoes. Rusty, jagged metal and glass are often found in swimming areas, so proper footwear can prevent serious cuts and the need to go for a tetanus shot. When detecting in the ocean, proper footwear can also protect you from some of the unsavory critters that can be found on the ocean floor. Stay aware of possible rip currents.
Use of knives and other cutting tools such as trowels can also cause injuries. I recently cut the back of my leg with my long-handled water scoop when I was not paying attention to what I was doing.
Whatever you are detecting on the land of in the water, be aware of the kinds of critters you may run up against. In the ocean, it could mean jellyfish, sharks, skates, etc. On land, it could mean poisonous snakes or insects, or animals that bite.
And though it's something you may not have considered, some metal detector users have actually been mugged. Because you are wearing headphones, it is easy for someone to sneak up on you.
For the most part, metal detection is a fun recreational hobby. But just in case, you should be prepared for injuries and keep a first aid kit handy in your car. Have some bug repellent handy in case the bugs are biting. But most of all, just be aware of your surroundings and what you are doing.