Best Underwater Metal Detector 2021: Buying Guide

metal detectors for under water

There’s nothing that can beat the excitement and euphoria that comes with pulling a rare relic or even a gold nugget from the ground.

However, before you get too cocky, treasure hunting is a challenging task, especially if you going to take your prospecting underwater.

Contrary to land prospecting, underwater treasure hunting comes with its unique challenges. See, hunting for treasure underwater is considered tougher than it is on solid ground, and few metal detectors can go below the water to search for the precious metal.

Thankfully, technology has made it easier to access underwater, and with the best underwater metal detector, we now have a much better chance of unearthing gold underwater.

Be as it may, with a variety of options in the market, choosing the best metal underwater metal detector is quite a challenging task.

Thankfully, I am here to provide you with a list of the top 5 detectors in the market; in the review guide below, I will highlight the top 5 underground metal detectors in the market, and hopefully, by the time you’re through with the text, you should have found one that will fit your needs.

Top 5 Underwater Metal Detectors Reviews:

1.Fisher 1280-X Aquanaut (Best for Deep Water  250 ft)

Fisher 1280-X Aquanaut is one of the few models that won’t dig deep into your pocket but despite this, it’ quite a functional detector, and it even outclasses some of the more premium models. Let’s see what Fisher has in store for us.

Deep Diving Capabilities

One of the major highlights that probably elbows this model from the rest is the deep diving capabilities.

Fisher 1280-X lets you dive up to 250 feet, which is 50 feet more than most competing models, and so, I found it a popular choice for the serious divers.

It’s also a great alternative to the Garret AT Pro, which has a limited diving capability of 10 feet in shallow freshwaters.

2.4 kHz Frequency

Fisher 1280-X, however, comes with a depressing 2.4 kHz, which is quite lower than a majority of other models within the section.

I found out that though this low VLF detector provided greater depth compared to the higher frequency alternatives, it was more likely to suffer from interference when hunting in the wet sand.

Ground Balance

To counteract the effects of low frequency, Fisher has fitted this underground metal detector with a manual ground balance as well as a discrimination feature.

Combined, these features will help to eliminate trash such as iron pieces, and I loved that I could adjust their settings to suit my treasure-hunting needs, including customization for gold hunting.

Quartz—Crystal Circuitry

One of the interesting features I found on this underwater metal detector is the Quartz-Crystal Circuitry, a technology that is designed to ignore the small trash items.

I found this technology quite handy, especially considering that digging a plug when diving can be quite a challenge, and so, the extra circuitry to help filter the bad target is definitely a welcome addition to this detector.

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2. Garrett AT Pro Underwater Metal Detector (Best for water and land)

Garret AT Pro, part of AT Series, which also includes the Gold and Max, is arguably Garret’s most famous metal detectors.

Typical of the AT Series models, this metal detector is built to provide professional standard performance for a reasonable price. But how does it really compare to other detectors, and how is it effective at hunting treasure underwater? Let’s find out.

Waterproof All-Terrain Capabilities

If you’re looking to invest in an underground metal detector, it would only make sense that you first consider its waterproof capabilities.

Thankfully, AT Pro doesn’t disappoint because it’s fully submersible to a depth of 10 feet, which I found quite great for hunting in the shallow water, ponds, and creeks.

Even so, I was disappointed as I could not use the model for deep-sea diving, hunting shipwrecks, or scuba diving.

Nonetheless, for what its worth, this model is fully submersible, contrary to a majority of the detectors that only have a waterproof coil.

Furthermore, AT is a highly versatile model, and it allowed me to take my hunting expedition from the water to the solid ground.

15 kHz Operating Frequency

Garret AT Pro comes with a 15 kHz frequency, which I found quite higher than a majority of the VLF detectors in this price range, and it did a brilliant job of detecting the small targets and offered an incredible target separation.

However, I was a bit concerned with the single frequency VLF operating mode because it’s not effective on salty and highly mineralized grounds, though the manufacturer claims it can be used in saltwater, this isn’t just the case.

Don’t get me wrong; you can still use the AT Pro on salty water, beaches, but if you plan to get into the water, you’re going to get a lot of chatter, which might limit your search capabilities.

However, it’s worth noting that this isn’t just a limitation with Garret AT Pro, but with the single frequency technology.

Ground Balancing

I was, however, reprieved when I found out that AT Pro featured a ground balancing feature, and this canceled the single frequency limitation.

This metal detector has both automatic and manual ground balancing capabilities that played a crucial role in ignoring signals such as iron and salt from the ground while reducing chatter, which I found quite handy considering that I love taking my treasure-hunting in highly mineralized soil.

Digital Target ID

I was impressed by the large numerical target ID on the center screen, which is based on a 0-99 scale, providing more accurate information about the target composition. Though this is a standard feature among mid-range detectors, Garret ensured that this model was fast at providing results.

Notch Discrimination

This search mode allows users to “discriminate” or rather find treasures with conductivities above the iron, and I found it quite handy as I can now easily eliminate the trash in my search.

Iron Discrimination

This is yet another exciting search mode that features 40 segments, allowing users to exclude and eliminate all the ferrous targets, including junk and nails.

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3. Garrett Sea Hunter MkII (Best for Mineralized Grounds)

I’ve to admit that Sea Hunter is on the more expensive side but its definitely worth it, especially considering that it’s built with reliability and quality in mind. Moreover, it comes with a variety of exciting features, and the user experience is just on another level.


Whether you’re looking to scuba dive, snorkel or beach hunt, the Garrett Sea Hunter MkII is the cream of the crop. I love its durability, ruggedness, and, more importantly, the fully waterproof cutting-edge design, with an operational depth of 200 feet that makes it ideal for use on both freshwaters as well as saltwater hunting.

Pulse Induction

Contrary to the previously reviewed metal detectors that use a VLF technology, Garrett Sea Hunter MkII uses PI, or rather pulse induction scheme, which isn’t generally affected by brackish water or even the highly mineralized ground.

In any case, PI was specifically designed for hunting in the highly mineralized locations. However, I was quite disappointed that the metal detector did not feature a discriminator, which would have made our search more challenging.

The good news, Garrett Sea Hunter Mk II, features some functions that can be likened to the discriminator, known as the Discrete Trash Elimination.

Discrete Trash Elimination

Discreet Trash Elimination is a groundbreaking and proprietary technology that functions more or less like the VLF discriminator by expertly eliminating pull-tabs, while at the same time targeting the smaller valuable with a similar frequency such as gold nuggets.

Why I love this technology is because previously, PI metal detectors usually eliminated the valuable treasures with other junk targets, but this feature allowed me to eliminate the trash and target the treasures alone.

Three-Part Shaft

I was also impressed by the fact that the manufacturer has designed this metal detector for the ultimate versatility thanks to the three-part shaft system that promotes ease of use in different environments,

However, there’re a few gripes to this underground metal detector including the absence of a pinpoint mode, meaning it was harder for me to get a precise target.

Additionally, the detector didn’t provide a visual identification, which was quite disappointing, especially considering what I had to pay.

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4. Fisher CZ21-8 Underwater Metal Detector (Best Premium)

Fisher CZ21-8 is a high-end underwater detector that can be used in both fresh and saltwater. Tying up with its sibling, Fisher 1280-X Aquanaut, the Fisher CZ21-8 will allow you to take your hunting expedition up to 250 feet depth.


Fisher CZ21-8 is built with durability, and the overall toughness is simply on another level. The housing on this metal detector is sturdy, less prone to breaking over time, but more importantly,

it’s submersible and has a generous waterproof capability of up to 250 feet. So, whether you’re planning to scuba dive, or take your hunting deep into the sea, Fisher CZ21- 8 will stand up to this task.

Dual Frequency Technology (5 & 15 kHz)

The dual-frequency feature is probably the biggest highlight of this metal detector. Though some users claim the Fisher CZ21-8 frequency does not have better discrimination, what I can tell you is that this mode will give you a slightly better depth on the beaches, and it will provide faster signal recovery.

The performance of the Fisher CZ21-8 is further bolstered by a concentric coil design that made it easier for pinpointing for discovering the exact target.

However, I would have loved to see a Double D design coil as the concentric coil was pretty limited on the area coverage.

Ground Balance

Fisher CZ21-8 comes with a manual ground balance that I found quite handy in eliminating the iron trash and reducing instances of chatter.

However, unlike the auto ground balance, which relies on the machine to determine the best setting, the manual mode has a learning curve as it depends on your input.

The ground balance feature was further bolstered by an audio tone target id that allowed us to distinguish iron from gold.

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5. KKMOON Handheld Detector (Best Budget)

If you’re looking for a simple and no-frills metal detector, KKMOON Handheld Detector is the ideal option. Despite its simplicity, KKMOON Handheld Detector is an incredible product for the scuba divers and snorkelers who want to get into metal detecting.


As I had mentioned in the introduction, KKMOON Handheld Detector is a simple detector, and I loved the compactness it offered as it did not pose any problem, even to the beginners.

If you’ve done metal detecting before, I know you understand how challenging it can be to hover a full-size detector in the water.


The overall design is specially sealed to allow metal detection even at depths of 98 feet. It’s not the highest depth I’ve come across, but I have to admit that it was quite impressing, especially considering how affordable it is.

Pulse Induction Technology

Like the more premium Garrett Sea Hunter Mk II, KKMOON Handheld Detector operates using a Pulse Induction Technology, and I found this quite handy as it allowed us to treasure hunt in the brackish waters, black sand and even the high mineralized sands without getting any interference.

Automatic Tuning

I found the KKMOON Handheld Detector easy to use, thanks to the presence of a technologically advanced microprocessor designed that offered a hands-free operation and required no adjustment of any kind.

Stable Detection Depth

The advanced circuitry maintains a stable detection distance throughout the lie of the battery, while an LED signal alongside a vibration will indicate the detection of metal.

I was impressed by the target distancing feature that increased the pulse vibration and light intensity as I got closer to a metal target.

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Top Underwater Metal Detector Buying Guide

In the section below, we shall look at some of the crucial features that you should consider when purchasing an underwater metal detector;


The first and crucial factor to consider is waterproofing properties; after all, it wouldn't make sense having a detector that cannot be used underwater.

While at it, you should also consider the depth levels. Ideally, the higher the depth levels, the better, and if you’re going for underwater treasure hunting in deep-sea diving, you should get a detector with a water depth of at least 200 feet.


Metal detectors are broadly classified into VLF and PI and both of these modes have their distinctive benefits and drawbacks.

PI detectors, though they lack discrimination, are the ideal choice for the salty waters and the mineralized grounds since they’re not generally affected by these conditions.

In addition, they offer incredible sensitivity and can function at great depths. The VLF detectors, on the other hand, are general type unit that is less inexpensive than the PI detectors, and they offer decent sensitivity, but often struggle in the ground with heavy mineralization.

Target ID

You also need to consider how a metal detector notifies you while you’re underwater. The standard models offer notification beeps, but these only work well in calm water-Consider, a detector that also includes an LED indicator when the audio is not loud enough.


Whatever model you purchase, consider whether it comes with accessories. Some of the premium and high-end models come with accessories such as waterproof headphones, Mesh Pouch, Chest harness steel trowel, and more.


Generally, metal detecting is both fun and rewarding, but it’s crucial that you get an ideal metal detector.

To know whether you have the right detector, you need to ask yourself several questions including how you’re going to use the detector, where you’ll use the detector, whether you’ll be diving, or how deep you’ll be diving.

If you consider all the above questions, you are definitely going to get a model that will satiate your treasure hunting needs.

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