This article contains references to products from one or more of our advertisers. We may receive compensation when you click on links to those products.
Here’s a look at the best underwater metal detectors to use scuba diving or snorkeling in 2018.
Buying a metal detector for the first time can be nerve-wracking, especially if you have no idea what to actually expect from this type of machine.
It becomes more even more complicated when your goal is to hunt for valuables and possible treasures underwater.
If snorkel-hunting or scuba hunting is your goal, you will definitely need an underwater metal detector. Here’s what you should be looking for:
1. Depth Capacity
Depth capacity is the ability of an underwater metal detector to resist water damage. Not all water detectors can be submerged safely to whatever depth on pleases. There are limits, depending on what type of machine is available.
The Fisher CZ21-8 underwater metal detector is one such detector that can submerged to a maximum of 250 feet.
In case you don’t need a metal detector that can go all the way down to hundreds of feet, you have the option of using detectors like the Whites MX Sport waterproof metal detector, which has a 10” DD search coil (ideal for clear sands and terrain) and even comes with its very own waterproof headphones.
Headphones are definitely tricky when you’re going underwater. Many underwater metal detectors have their headphones built into the unit itself to prevent any leakage and subsequent water damage from being submerged.
Be sure to check how the metal detector is made or at least, how it was designed to resist water. Saltwater hunts are different from land and freshwater hunts. If your goal is to hunt in a saltwater environment, check if the metal detector can withstand saltwater.
Another unit worth looking at is the Tesoro Sand Shark that has been rated safe for submersion up to 200 feet and was designed to produce accurate hits when used in deep seawater environments.
2. Sensitivity, Controls and User-Friendliness
When it comes right down to it, a metal detector is most useful when it can actually be set to the right sensitivity level and it can deliver the correct signals to the user. Each underwater metal detector has its strengths and weaknesses when it comes to bridging the technical aspects of the machine and the user, who isn’t always an expert on metal detecting. How do the manufacturers make it easier for people to use metal detectors?
In the case of the Fisher CZ21-8 underwater metal detector, it was equipped with dual-frequency Fourier domain signal analysis and a touch button interface that makes it easier to shift from one search mode to another. “Search mode” is a term that refers to frequency ranges when the machine is sending out waves to the environment.
The higher the sensitivity, the more likely you’ll get ‘false hits’ or pings from anything that is remotely metallic in the sand or soil. This metal detector also uses 3 Tone technology for easier identification of ‘hits’ during a hunt.
The handle is fully extensible, though you may want to collapse the length of the handle when you’re using it underwater as it can be difficult to metal detect when the arm is fully extended.
The Tesoro Sand Shark on the other hand, features an advanced Digital Pulse Induction Technology.
This simply means that this metal detector relies heavily on micro processing technology to deliver results.
One upside of using this model is that Digital Pulse Induction Technology was designed for saltwater environment and wet beaches. Salty environments have an impact on the accuracy of metal detecting and it’s always a good decision to buy a unit designed to detect metal in salty environs.
The Whites MX Sport waterproof metal detector on the other hand, features “search modes” that makes it easier for the user to move from one environment to the other.
Available search modes are: Relic Mode, Coin/Jewelry Mode and Salt & Freshwater Target.
Let’s discuss each of these modes.
In ‘relic mode’ the metal detector will use a frequency range that will detect the most common metals used for old and historical items, like iron.
Coin/jewelry mode will raise the sensitivity of the metal detector to its highest range because you need maximum sensitivity for gold and other precious metals.
The third search mode, “salt and freshwater target” will enable the metal detector to pick up signals in a submerged environment, where signal interference can be a real problem.
The Garrett AT Pro metal detector features a slightly smaller search coil at 8.5 x 11” (compared to the usual 10” coils found in other brands) and is ideal for both freshwater hunts and saltwater hunts.
This is the essential distinction of the AT Pro – it was designed for two kinds of environments.
Many other brands adjust the settings of their metal detectors to work with seawater specifically. But what about rivers, ponds and lakes? These are all freshwater bodies (well, some lakes are freshwater and salty at the same time).
The Garrett AT Pro is ideal for catching relics, coins and jewelry. However, the downside is it cannot be submerged to more than 3 meters of waters.
So despite the attractive price point and features, remember that this cannot be used if you are shipwreck hunting or just scuba hunting in general.
And as we end our discussion, let’s talk about batteries. Metal detectors run on different kinds of batteries. The question is: which one is most economical?
In our experience, those that run on higher voltages tend to have higher capacities. However, smaller batteries like AA batteries are generally cheaper to replace when the batteries are worn out.
Our advice would be to find rechargeable batteries as these tend to be built more robustly and are cheaper in the long term than disposable batteries.
Yes, you are going to spend a little amount of money on the charger and the number of batteries needed for your metal detector but in the long term you are going to be happier with the results.
The downside to this is you have to charge your batteries of course, but this is far easier and more environmentally friendly than disposing of six or eight AA batteries every time you run out of juice.