Have you ever been out in your backyard with a metal detector and found some old coins? Or perhaps you have gone treasure hunting with friends and come across some gold nuggets while searching through the sand?
If this sounds like fun, then you might want to consider becoming a metal detector enthusiast.
Metal detectors can also be used with scuba gear to locate valuable treasures beneath the ocean’s surface. While scuba diving is very different than metal detecting, there are many similarities between these two hobbies. Many people who enjoy one activity often do the other too.
Metal detecting underwater involves using a specialized metal detector to search for and locate metal objects that may be submerged in bodies of water, such as rivers, lakes, and oceans. This activity can be a fun and rewarding hobby, as it allows you to search for and potentially discover hidden treasures or artifacts from the past.
To get started with metal detecting underwater, you must obtain a waterproof metal detector and familiarize yourself with its operation. You will also need to have some basic scuba diving skills and the necessary equipment to conduct searches underwater safely.
Before beginning your search, it is important to research the history of the area in which you will be searching and any relevant laws and regulations.
You should also obtain the necessary permits and follow all underwater metal detection guidelines, such as respecting private property and sensitive cultural and natural resources. Additionally, follow all local, state, and federal laws related to metal detecting and artifact collection. Finally, take safety precautions while diving, including using proper diving equipment and following proper dive protocols.
Underwater Metal Detectors vs. Diving
Before we get into what makes an ideal metal detector for underwater use, let’s take a quick look at how they differ from scuba equipment.
Scuba diving involves breathing air mixed with pure oxygen directly from tanks strapped to your back. The diver must wear heavy protective gear, including a full face mask, gloves, fins, and buoyancy control devices called “buoyancy compensators,” which keep the diver upright even when they have no air left in their lungs.
Metal detectors are designed to detect metallic objects buried underground. Once turned on, they emit electromagnetic waves which travel through the ground until they hit a target object. A tiny receiver picks up the reflected signals and displays them on a monitor screen. If the signal strength is strong enough, the operator knows that there is a metal object nearby.
Both scuba divers and metal detector enthusiasts need to determine how deep they should go before starting their search. This is done using specialized equipment such as pressure gauges and dive computers.
Divers usually use depth meters to measure depths during dives. These instruments give readings in feet or meters below sea level based on changes in atmospheric pressure.
Metal detector users rely on specialized software to calculate the depth of targets detected by their machines. Some units include built-in GPS systems, which allow the user to map out where his finds were located.
While scuba diving involves breathing compressed air, metal detectors produce electrical pulses instead of inhaling gases. This means that metal detectors don’t require extra equipment beyond what would typically be needed for outdoor use.
However, if you plan to use your metal detector in shallow waters, you’ll probably want to invest in a pair of fins to ensure you can stay in place. Also, since metal detectors cannot breathe, you won’t need a regulator or tank.
While scuba diving requires training and certification, anyone can start using a metal detector without undergoing extensive instruction or testing. All you need to know about basic safety precautions are included in the instructions supplied with your unit.
Since scuba diving is an entirely different hobby from metal detecting, it’s important to remember that the equipment needs to be treated differently. While you wouldn’t want to risk damaging your expensive scuba gear, you shouldn’t treat your metal detector any worse! Here are some tips to ensure that you’re doing everything safely:
- Always read the manual thoroughly before attempting to use your new metal detector. Make sure you understand all of the safety precautions listed therein.
- Keep your metal detector away from magnetic materials, including speakers, televisions, microwave ovens, cell phones, etc.
- Don’t leave your metal detector unattended unless switched off. If you accidentally forget to turn it off, switch it to “standby” mode.
- Never run your metal detector over a power cord or cable. Doing so could cause damage to the wires inside and possibly create a fire hazard.
- Don’t point your metal detector toward yourself or others. It emits high voltages, which could harm someone close to it.
- Always stay clear of overhead power lines and fences outdoors when using your metal detector. Be aware of your surroundings and never stray far from civilization.
- Never bury your metal detector in the ground. As soon as you dig down deeper than 6 inches, you increase the chances of picking up interference caused by electrical current from power lines or other sources.
- Be careful around water. Metal detecting near bodies of water presents additional dangers because the water acts as a conductor of electricity. Never submerge your metal detector in water if it is not designed to be waterproof.
- Always carry a spare battery charger with you whenever you venture outside. Keeping a backup charged battery on hand ensures you won’t miss anything within range. Most modern models only last 2-4 hours, depending on your activity.
- Take care when handling your metal detector after each use. Keep it clean and dry, and store it correctly according to the manufacturer’s instructions.
- Make sure you follow all local laws regarding metal detector usage. Don’t trespass onto private property, and don’t disturb wildlife.
As mentioned earlier, scuba diving is another trendy hobby alongside metal detecting. Although the two activities share many similarities, there are also significant differences.
Pulse Induction (PI) Detectors
Pulse induction (PI) metal detectors are commonly used by hunters looking for lost game animals. These machines generate low-frequency radio waves that penetrate the ground to a certain depth and bounce off buried metal objects.
The resulting reflections are picked up by a sensor located underneath the metal detector. Since PI metal detectors send out continuous radio waves rather than pulses, they aren’t capable of pinpointing the exact location of a target. Instead, they provide information about its general distance and direction from the detector.
PI metal detectors are excellent tools for hunting because they offer reasonably good discrimination. They can distinguish between metal objects made of iron ore and those made of bronze, silver, copper, lead, tin, and zinc, among others.
PI metal detectors generally cover a wide range of frequencies ranging from 1 MHz to 10 MHz. Lower frequencies are more effective at detecting smaller targets, whereas higher frequencies are better suited for more oversized items. Most PI metal detectors will automatically adjust their operating frequency accordingly.
PI metal detectors are relatively inexpensive compared to other types of metal detectors. They are also easy to use and maintain. Because they lack sophisticated targeting capabilities, they are not recommended for serious treasure-hunting expeditions.
Very Low Frequency (VLF) Detectors
Very Low Frequency (VLF) metal detectors are primarily intended for use in archeological digs. Archaeologists use these machines to uncover artifacts hidden beneath the earth’s surface. Unlike PI metal detectors, VLF detectors send out short bursts of energy rather than continuous waves.
VLF metal detectors are highly sensitive and pick up virtually every metallic object buried deep beneath the ground. Unfortunately, VLF detectors are less discriminating than PI metal detectors, meaning they cannot differentiate between various kinds of metals. Consequently, VLF detectors are useless for hunting purposes.
VLF metal detectors function by sending out a series of short radio pulses. Each pulse lasts approximately 100 milliseconds and consists of three distinct components. The first component is a feeble initial pulse lasting several microseconds. This part of the pulse helps to stabilize the oscillator circuit. The second component is a weaker intermediate pulse lasting 5-15 microseconds.
This stage of the transmission provides a means of amplitude modulation, allowing the detector to create a magnetic field. The third component causes the radio pulses to bounce off metallic objects and alert the detectorist.