Seeking the Best Underwater Metal Detector? Dive Into This!

Best Underwater Metal Detector

If hunting for buried treasure—or submerged valuables—tweaks your leisure-time fancy, then you are probably on the hunt for an underwater metal detector.

Before googling around for retailers and suppliers, ask yourself whether you want to scour salt or fresh water. Then ask exactly where you will search—e.g., around tide line, in the shallows, or on deep dives.

Then, start your pursuit for the perfect performer, which will either be a pulse induction (PI) detector or a very low frequency (VLF) model.

If you are already dizzied at this introductory level of understanding underwater metal detectors, heed the favorites list from our treasure-finding experts and more details from our subsequent buying guide.

Best Pulse Induction (PI) Underwater Metal Detectors

The PI detector is preferred for deeper saltwater and other conditions heavy in ground minerals or metals.

The PI detector does not require movement to perform, stationary positions or just a slight movement will still detect your targets. It works well in these settings because of its high-voltage pulse, which it directs to the ground below its search coil.

If no metal is detected, a spike in voltage is measured and then decreases. If metal is identified, the detector conducts some of its voltage. This waylays the time taken for the voltage to return to zero. This process acts as the identifier for the user.

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Since different metals conduct electricity at various levels, the user must guess which metal is beneath the coil. This can require some blind digging. However, the power and range allow the user to find targets not attainable by the very low frequency (VLF) detectors (described in the VLF section of this guide).

Garrett Sea Hunter Mark II w/ Garrett Pro Pointer AT – For the serious diver 


  • Great identification capabilities
  • Easy to operate
  • Good depth capability


  • Pricey
  • Heavy at 8.2 lbs.

This top-notch PI performs more discriminately than its competitor, the Sand Shark.

The Garrett Sea Hunter Mark II, mostly due to its groundbreaking, patented discreet trash elimination mode, can discern a pop-top from a ring or a coin. Like many other Pis, the Sea Hunter keeps on pulsating in wet saltwater sand and around ground minerals.

In its all-metal, deep-seeking mode it proves very effective up to 200 feet deep with its standard 8-inch coil. Endorsed by treasure-seeking paragons Mel Fisher and Bob Marx, excels in finding the right type of buried objects in the ground heavily wrought with minerals. Its long stem design allows for long, deep treasure hunts.

Moreover, its adjustments are quite basic: Hit the power button and adjust the dial to one of two search modes. Its threshold sets the base audio level. This unit comes with submersible headphones by Garrett.

At the higher end of the price spectrum, the Sea Hunter Mark II finds favor with serious divers who favor ease of operation and a more definitive search.

JW Fishers Pulse 8X Waterproof Metal Detector


  • Highly acute identification of metal objects with negligible interference from minerals
  • Totally waterproof and well armored for deep dives
  • Negative buoyancy
  • With connector, interchangeability of coils for specialized searches
  • Good for land or sea
  • Comes with the hip-mount kit, underwater coil connector, headphones, and rugged carrying bag


  • At the highest end of the price scale
  • Could use a hike in the two-year limited warranty
  • Weighty, especially out of water

Used by professional searchers—military, law enforcement, intelligence agencies, commercial divers, and salvagers—the JW Fishers Pulse 8X Underwater Metal Detector bandies a commensurate price, as much or more than a reputable riding lawn mower.

In return, however, you receive a tough-as-nails, solidly waterproof, and extremely sensitive detector with a connector to change the sizes of coils. Its identification capacity—sorting the jetsam from the jewel—hinges on its more sophisticated representation of what lies buried beneath the ocean floor.

The Fishers Pulse 8X uses visual and audio indicators. Once a metal object is found, an alarm sounds, and a visible meter indicates the strength of the signal. Detectors relying only on audio signals or even blinking lights don’t muster the same ID capacity as the Pulse 8X, which runs on a nine-volt, rechargeable battery pack.

Because the audio alarm is plenty loud, you won’t need to replace the included headphones with a more powerful pair. It is designed to easily alert divers in a couple hundred feet or more of water and up to six feet from the ocean floor. Also with the diver in mind, the Pulse 8X contains enough negative buoyancy to keep it from floating away while the diver concentrates on digging for the targeted item.

The detector’s tough shell—consisting of a quarter-inch, single, solid casting with seamless brass inserts coupled with a half-inch thick, acrylic faceplate—lends to its gravity and overall resilience to wear and tear.

This is your Hercules of detectors and if you are totally dependent on it for part or all of your livelihood, the money spent is worth the return.

Tesoro Sand Shark Underwater Metal Detector


  • Goes deep
  • Covers a lot of ground little time
  • Lifetime warranty offered
  • Waterproof and effective up to 250 feet deep
  • Under 4-1/2 lbs.


  • Need very good headphones because of the low threshold volume
  • Lack of target identification requires much digging
  • Drains battery relatively fast because of its effective range

For speed and depth, the Tesoro Sand Shark, a PI detector offering a non-standard 10.5-inch coil, proves ideal for saltwater mongers who don’t mind digging upon each alert.

Though you can go with an 8-in. coil for this model, the extra 2 in. of the coil allows you to cover more area at a quicker rate. You just need to be ready to dig at every detection signal because the tone on the Sand Shark does not adjust for different object compositions. You won’t know what you are about to find until the sand has settled, much like other PI detectors.

Again, the PI is all about depth and the ability to render readings amidst ground minerals, unlike the low-frequency (VLF) models. The Sand Shark, however, will require a bit of a learning curve when it comes to the dials. In regard to threshold and volume, for instance, the ideal level is that which emits a very low, steady hum.

As for adjusting the sensitivity, the manual suggests a halfway position, but the best way to get used to all the dials and their ideal settings is to take the Sand Shark out for a couple of spins in dry sand along the beach. You’ll find a lot of trash, for sure, but you will also gain a quick lesson on what this detector’s four dials are all about.

Soon you will be able to winnow through the detritus on the way to gold, coins, or jewelry. Another important note: Go through the process of obtaining the Tesoro warranty; it is worth it for this upper-mid-range priced detector.

Garrett ATX PI Military Grade Metal Detector – The most easy-to-use right out of the box


  • Great discrimination capability with its multiple settings
  • Rugged & Portable
  • Three different sizes of search coils from which to choose
  • Easy to read display, even in bright sunlight (though not an LED display)


  • Headphones not waterproof
  • Not for those hooked on LED displays
  • A bit heavy

Another pro-level detector, the Garrett ATX Military Grade Underwater Metal Detector compares to the JW Fishers Pulse in price and performance, but its look does not.

In fact, its look is like no other metal detector. Covered in army green with some green camo donning the battery pack on top, the ATX smacks of ruggedness if not some sort of weaponry with its shaft rings for collapsing the detector.

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You can telescope it down from its full extension of 68 inches to only 20 in. long—just right for the carry-on rack of a plane. Though there are a multitude of settings that may appear intimidating to first-time users of this detector but know that most of these allow you to zero in on individual compositions of targets while casting out detection of the flotsam or unwanted materials.

In fact, our experts pick this one as the easiest to use right out of the box. However, it weighs around 7 lbs. and contains some bulk, but neither hinders its maneuverability unless you suffer a chronic shoulder or elbow condition.

Unlike our other picks on the upper end of waterproof metal detectors, the ATX is not designed for deep-sea treasure hunts. Its waterproof capabilities go as deep as 10 feet. And though the speaker is waterproof, the accompanying headphones are not. Still, it roves fast and effectively with a detector frequency of 730 pulses per second.

Garrett Infinium Metal Detector – Best Underwater Gold Detector


  • Handles extremely diversified terrain
  • Deep-seeking
  • Light
  • Good value on the dollar spent


  • Some complaints of loose stem construction and wobble around the coil
  • It May take a dry run or two to become oriented to settings and best frequencies

We could justifiably place a gold star by this detector, if only for the fact it is regarded as one of the best deeply buried gold identifiers on the market.

The Garrett Infinium is also one of the most versatile when it comes to land and water while rating high—but not highest—on our scale for material discrimination in virtually all of its detection depths.

It relies on only three controls—discrimination, threshold, and automatic ground track (with lock, slow and fast)—to accomplish such versatility. Because of its adjustable operating frequency, it can isolate its search to such sought-after metals as gold.

On the other end of its agility, a reverse discrimination setting pinpoints most iron items. It uses a large 10 by 14 in. power DD search coil and finds targets as deep as 200 feet below the water surface (optional submersible headphones are required, however).

Whether scanning high mountain watersheds for gold, beyond the Caribbean reef for pirated treasure, or the grounds of an ancient skirmish, the Infinium, with its groundbreaking Advanced Pulse Induction™ technology, answers your call.

Best Very Low Frequency (VLF) Underwater Metal Detectors

Not as complex as the PI detector, VLF technology is generally applied to less expensive detectors in the entry level to intermediate user market.

It sports two closely located coils, one that sends an alternating low-frequency current produced by an oscillator and directed to the ground. If it detects a metal object, an alternating current passes through and around the item to cause an “eddy” of current. This creates another magnetic field, which is picked up by the second coil and signaled to the user via an alert through the control box.

Unlike most PIs, the VLF detector requires movement or a swinging action by your arm in order to function. It also cannot block out interference from wet sea sand, ground minerals, and other metal-ridden environments as well as the PI detectors.

Garrett AT Pro Waterproof All-Terrain Metal Detector – Dual Audio Mode


  • Good discrimination capabilities
  • Performs in versatile environments
  • Waterproof stem and coil
  • Extremely light
  • A variety of optional coils for specific purposes


  • Standard headphones are not waterproof
  • No backlight or LCD makes the middle of the display hard to read

Considered a high-performance metal detector for a mid-level price, the Garrett AT Pro stands apart from the VLF pack mostly due to its dual audio modes and fully waterproof construction—with the exception of its standard headphones. Garrett offers an optional waterproof set, however.

The dual audio mode allows the Garrett AT to emulate some PI detectors to the extent of identifying differing metals. Unlike the standard binary audio, the AT’s pro audio mode sends an oscillating audio signal when two different metals or compositions are found beneath the ground and under the coil. This audible fluctuation also occurs when one object is deeper than the next.

Essentially, this technology enables the AT to better discriminate between trash and earnest targets, eliminating some blind digging. It also features a faster recovery speed on multiple objects than many other VLF detectors and high-resolution iron discrimination.

Its waterproof components are limited to 10-foot depths, but for shorelines, near piers, swimming holes or streams, the AT provides ample prowess for anyone pursuing long, lost valuables.

Fisher 1280X-8 All-Purpose Underwater Metal Detector


  • Collapsible
  • Easy to operate
  • Optional coil sizes
  • Hip and chest mounts
  • Versatile for freshwater or saltwater
  • Battery life rated for up to 75 hours


  • A little pricier than some VLFs
  • The number of batteries required adds to the heft

Priced a little bit higher than the Garret AT Pro, but still well under $900, the Fisher 1280X with an 8-in. coil can pinpoint targets in freshwater or saltwater as well as dry land.

Perhaps being a little easier to use right out the box than the Garrett AT Pro warrants the extra hundred bucks. It needs no fine-tuning, no threshold, and no ground balancing. Submersible to 250 feet, the control box can be easily detached for hip mounting, like most of our picks. Plus, an optional chest mount harness is available.

Like Garrett’s ATX, this Fisher detector telescopes down for easier packing, but you will need to search at full extension in most situations. The 1280X finds fame with freshwater foragers but its longer battery life (because it uses eight AA batteries) and its waterproof features cater to saltwater searchers.

In fact, like its brother the Aquanaut, Fisher designed the 1280X for saltwater use. You simply need to adjust the sensitivity and discrimination controls. For the money, this unit will serve the multiple-terrain treasure hunter well.

Minelab CTX 3030 Waterproof Metal Detector with GPS


  • Great detection and discrimination capabilities for a VLF
  • Easy-to-read display
  • Features GPS
  • Outside of deep diving, very versatile and tough
  • Good at reading iron and conductivity of targets


  • At the top of VLF price ranges
  • Beginners will need some schooling
  • A little heavy
  • The control box does not detach for optional mounting
  • Could use a little more length than its 55 inches
  • Headphones not waterproof

This is your Porsche of VLF detectors. Unlike the preceding pick, the Minelab CTX 3030 may not tout extreme versatility, especially with its 10-foot maximum water functionality. However, it nods to technology and usability qualities.

To start, it features wireless audio, a bright, full-color LCD display, and something not common among detectors—a GPS receiver. These all add up to more efficient searching and the ability to quickly relocate honey holes because of the GPS.

It is not necessarily a diver’s detector, though its advanced FECO discrimination capabilities definitely find a home in shallow saltwater. Its FBS 2 technology allows for multiple frequency transmissions (see our buyer’s guide for more about frequency in general) from the coil to detector. It all equates to finding more varying targets in diverse ground conditions.

In this vein, its standard 11-inch, waterproof, Double-D smart coil covers your ground efficiently. Ten tailored search modes don’t hurt either. Two pinpoint options and 20 different discrimination patterns contribute to its effectiveness.

If you haven’t already discerned, however, this is one of those detectors you should take on a dry run or two after taking it out of the box. Otherwise, you might be spending more time fuddling than finding on your first outing.

Fisher CZ21-8 Underwater Metal Detector


  • Very lightweight at 2.6 lbs.
  • Easy to operate
  • Good coin discrimination
  • Very visible LCD displays and minimal buttons


  • A bit flimsy and not as rugged as higher-priced detectors
  • Not for the advanced treasure seeker or diver

Unlike the other VLF picks, the Fisher CZ21-8 is specifically designed for the entry-level salvager.

It keeps its display simple yet effective in its metal-discrimination capability. The amateur’s typical hunting grounds—beaches, surf, ball fields, or similar parks—prove ideal for the CZ21-8.

Its two-digit LCD readout is easy to see when checking out which kind of metal is beneath your coil. This eliminates a lot of scuffing for undesirables, such as pop-tops and hair pins or other dreck. It also comes with two coils for variations in search grounds.

The CZ21-8 offers great one-touch target pinpointing and superb coin-finding capacity, including its depth indications. This detector allows the amateur treasure seeker to grab and go after opening the box.

Buyer’s Guide: Everything You Need to Know About Underwater Metal Detectors

Are you a Sunday seeker of coins at the beach or park? Perhaps a diver who wants to complement your workaday income with some treasure-seeking adventure at the sea’s bottom on weekends? The beauty of underwater metal detectors lies in their variety. There is one for your purposes, no matter how specific. They also span a wide range of prices.

Finding the one just right for where you conduct your treasure hunts, however, requires some knowledge of technical terms and the types of detectors on the market. Knowing just the basics of where and how a metal detector works will greatly enhance your chances of finding the one that makes your pockets jingle and your search efficient.

VLF, PI, oh my! Which is better?

You can’t avoid technical terms when it comes to electronic equipment, especially underwater metal detectors. The first two terms bound to confuse the neophyte are VLF (very low volume) and PI (pulse induction). They relate to electronic pulses, voltages, electro-magnetic fields, and frequencies. (Please refer to the earlier explanations in this article about the differences between the two types of detectors.)

What you really need to know is which one is better for the type of salvaging that piques your interest.

VLF Underwater Metal Detectors – All The Facts

As earlier mentioned, a VLF must be waved or moved around with your arm, like stirring a gigantic drink, in order to produce a current from metals lying below. If motionless, the detector is no more reliable than the legendary divining rod. It is also virtually useless if a lot of salt water, black or wet sea sand, and aged, harsh, red soil surrounds the search area. In other words. This is due to the VLF’s vulnerability to interference from a high content of metal found in saltwater and the aforementioned ground environment.

As a result of such interference from other metals in the natural ground environment, a VLF will render a lot of false readings.

Unlike PI detectors, a VLF usually sports a noticeably lower price tag. It is often the tool of choice for beginners and amateur treasure hunters because of the price and the areas in which amateurs usually cut their treasure-hunting teeth: beaches, sporting fields, razed building sites, arenas, and parks.

If you are a treasure seeker on a budget who might want to dive for targets at times but mostly frequent the beaches and well-trafficked turf or sand, then there is a VLF unit that will meet your requirements. Indeed, there are some more expensive ones (e.g., the Minelab CTX 3030, the Garrett AT Pro, and the Fisher 1280X-8) that meet a diver’s demands in deep water.

PI Underwater Metal Detectors – Are They The Right Choice for You?

The attraction to this more complex type of detector revolves around its strength of range and waterproof qualities. Though you may not be able to discern what type of metal is being detected in some PI detectors, others incorporate technology that allows you to adjust the detector for greater differentiation of signals and, subsequently, better identification of metal.

With a PI detector, you do not need to waste elbow grease by waving the detector as required in a VLF unit. It will produce responses while perfectly still, even in such inherently high-metal grounds as black beach sand.

Those who dive yet want to comb the shoreline or surf will find a fully submersible, waterproof PI detector perfect for their purposes.

Because of their higher price (up to $3,000), the PI detector usually attracts the serious treasure seeker whose income is enhanced by what her detector finds.

Decoding the Word, “Frequency”

You will find this word often in the discussion of metal detectors. High frequency and low-frequency matter, depending on the type of treasure-seeking you conduct. Frequency relates to the number of electronic waves sent into the ground to detect metal pieces or fragments. For example, a frequency of 13 kilohertz means your detector will send and receive an electronic wave 13,000 times a second.

Water Resilience vs. Waterproof

Never shall the two be confused! A waterproof coil means something very different than a water-resilient coil. The former pertains to total submersion—as in diving—while the latter equates to resistance in rain or spray.

Does Coil Size Matter?

Short answer: Yes. Long answer: Depends on where and how you’re searching. The most common coil consists of 8 inches in diameter, generally considered an all-purpose size.

The smaller you go usually results in better the targeting of items—i.e., fewer trash targets and more meaningful signals. You save big time when searching for specific metals. The smaller coil also saves weight on your arm and a better balance of the unit, thereby sidestepping arm fatigue, crucial for the smaller, younger treasure hunter.

A larger coil covers a larger search area, of course, but detects more detritus in the meantime. They are therefore used in areas of low ground-metal content and are mostly free of trash.

A larger coil means more weight while searching, but some can bolster depth detection by as much as 15 percent: A plus and minus to using larger coils. It is therefore wise to buy a detector with exchangeable coil capacity.

The best of both worlds? Carry two coils and a detector that accommodates each size.

Power and Battery Pack

Battery life and power draw become crucial for those who dive deeper than 10 feet or cover a broad area when treasure hunting. Ground stabilization functions, as found with PI detectors, metal identifier technology, and active pinpoint functions draw power and drain batteries faster than detectors without some or all of these features.

Also, consider the amount of power consumed by your audio. When headphones are on your head you are drawing less power than when the sound is emitted solely through the detector’s speakers.

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Rechargeable battery packs, over time, will save you on power usage. They get the most usage from the type of electronics technology used in detectors.

Finally, consider the added weight of, say, eight batteries as opposed to two or four. You may gain more search time but also more fatigue from the extra weight.

Consider Your Essential Metal Detecting Accessories

When scouring the ground with a detector and digging for its finds, you will need a complement of tools:

  • Trowel
  • Dive Pole
  • Carry Bag
  • Sand Sifter
  • Sand Scoop
  • Mesh Pouch
  • Chest or Shoulder Harness
  • Pinpointer

Handy Tips for Finding the Right Underwater Metal Detector for Your Needs


When buying a detector, pay heed to its length and heft. If you are a slight person or a child who never felt worthy of playing basketball, you want a detector shaft length conducive to your height. You also want a detector on the lighter side as detectors go. If you find the proverbial gold mine and it motivates continued searching, you will be deeply discouraged with this hobby if you run out of steam all of a sudden.

 Going pro?

If you are seriously looking at treasure hunting as a cash cow, then buy the appropriate detector and accessories. Scour reviews such as those found here and open your wallet to those detectors that are priced in accordance to their power of depth and submergible qualities. The more serious you are about money, the more money you should be spending. That said, some detectors of less than $1,000 can accomplish the same as detectors of nearly $3,000. Don’t spend foolishly.

 Don’t buy older units just to save

If you are looking at used but reputable detectors because you are serious about treasure hunting but strapped budget-wise, be careful. As time progresses, so does the technology for both VLF and PI detectors. As technology improves and becomes standard, the price for it usually declines as time passes. An older unit without some of the newest innovations, without much extra cost, can quickly become a regretful purchase.

 Knowledge of the target helps

The more you know about the particular type of treasure you seek—where it is most often found and in what kind of cover—the more adept you will be about your purchase. Ask a dealer about the best detector for the particular item(s) you hope to find.

 Waterproof Headphones

If buying a waterproof detector, make sure the headphones that come with it are waterproof if you plan to dive. Buy a waterproof set if you must.

 Negative Buoyancy

If you are a serious treasure hunter, you probably want to search in deep water with a PI detector, which sometimes requires a lot of digging. You can be distracted from paying heed to a detector that may drifts. Be sure there is enough gravity in your detector to stay near your digs. They don’t make detectors for lost detectors—not yet, anyway.

 Give it a Trial Run

Some detectors are more complicated than others. Don’t feel silly about taking a pro-level detector over dry land—even a beach or volleyball court—just to orient yourself to its audio oscillations, its range, and speed of detection. It will save you time when it comes to finding real pay dirt.

Reaching a Final Verdict

An underwater metal detector is all about matching. It must match the treasure you seek, the time you spend seeking it, the amount of money you wish to spend, and your amount of muscle when it comes to wielding the device over great expanses. It also must match the amount of time you want to spend getting to know it. If you want out-of-the-box production, don’t waste money on a high-end or pro model.

Seeking the Best Underwater Metal Detector? Dive Into This!

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