Treasure Hunting

Underwater Metal Detectors

There are a variety of underwater metal detectors available on the market today.

When choosing a model you’ll need to decide whether you will be underwater metal detecting fully submerged while scuba diving, or whether you will use the detector at the waters edge.

Obviously, if you intend to fully submerge the metal detector you’ll need to ensure that all of its components are fully waterproof. Remember also to check the depth to which they are rated. Most fully underwater metal detectors are rated to 100 or 200 ft. These will suit all but the most experienced of scuba divers and professional treasure hunters.

If you are intending to use the machine at the waters edge where only the coil will be underwater, detectors classed as ‘waterproof’ will be sufficient.

Once you’ve decided upon the use of the detector you’ll then to need to decide on the type.

Types of Underwater Metal Detectors

In general, these are the four main types of underwater metal detectors are currently sold online and in stores.

1. Pulse Induction (PI)

Pulse induction metal detectors function by emitting a series of electronic pulses into the ground beneath them. The pulse circuit goes deeply into the ground through the water.

The pulses, which are short and quick, are quite sensitive to precious metals. However, they are not affected by ground minerals or wet sand. This makes them ideal for saltwater environments such as beaches.

The drawback is that this type of detector does not discriminate well between trash and treasure. This may lead to just as many poor finds as valuable discoveries. Pulse induction metal detectors perform well no matter what type of ground condition exists.

PI metal detectors do tend to be more expensive than their VLF brothers. However, heir increased effectiveness in marine environments is often regarded as outweighing their extra cost.

2. Very Low Frequency (VLF)

Very low frequency metal detectors function using a low frequency range of 3 to 30 kHz. This style of detector has good discriminating capability and can determine coins relics and jewelry from trash. Unfortunately, this style of detector can be affected by minerals contained in the ground or sand.

To overcome this, many of these models offer a sensitivity adjustment as well as a ground-balance adjustment. This provides an opportunity to tweak your settings based on your findings. If you do decide on a VLF style detector, be sure that it offers a salt water mode.

3. Beat Frequency Oscillation (BFO)

This is a very basic system and are generally used for very cheap or budget metal detectors. Essentially they are two rings of copper around iron or steel with a current passing between the two. The current is sent into the ground and if the signal is broken an audible beep is sent to the user.

The main thing to remember is that they have no way of discriminating between trash and a good find. They might be useful for those on a very tight budget or as a starter but for the serious metal detecting enthusiast I’d generally recommend they be avoided.

4. Broad Band Spectrum (BBS)

Broad band spectrum metal detectors function using a broad band of signals, emitted in more than one frequency. Capable of emitting up to 17 different frequencies, broad band spectrum metal detectors offer good discriminating capabilities. Since they use a range of frequencies they can identify a target more accurately. They can detect at varying depths better than a single frequency detector.

Additionally, false signals from salt water beaches and ground minerals are reduced. BBS metal detector technology has now been phased out, but I’ve included it in the case of anyone buying an older second hand metal detector.

Treasure Chest Underwater

Comparison Chart

Best Underwater Metal Detector: Brief Reviews

Charles and Eleanor Garret originally started Garrett Metal Detectors back in the 1960s.

Their main focus was to sell metal detectors that were built well and available at a reasonable cost.

They are known for selling a wide variety of metal detectors and are one of the leading companies in the industry at present.

Garrett Metal Detectors aims to continue building great sport and security detectors for many generations to come.

One example of their dedication to the industry is the Garrett AT Pro Metal Detector, which comes loaded with interesting features.

Product Highlights

At its very core, the Garrett AT Pro Metal Detector is designed to be an all-purpose machine powered by four AA batteries.

The AT in the product name refers to “All Terrain,” which means that it is a rugged machine with a highly durable exterior.

The metal detector can be used at a local park, beach, or desert. It is capable of handling anything you throw at it. What’s even better is that it needs minimal maintenance.

While the Garrett AT Pro Metal Detector can easily detect coins, jewelry, and relics, it has a high chance of finding gold nuggets, too, thanks to its 15kHz frequency and ground balance settings.

This detector also features an 8.5- x 11-inch DD PROformance coil, which provides a decent target separation and depth for a stock coil.

This is a perfect choice for an all-around coil if you need one that’s suitable for almost every situation.

However, if you’re looking for more specialist tasks, the company also offers a variety of other coils for this metal detector. This includes the nine- by 12-inch concentric coil and a sniper coil.

What is particularly great about this metal detector is that it is lightweight.

Weighing in at just 3.03 pounds, you can be assured that you will not get fatigued even when you use it for extended periods

What We Like:

The Garrett AT Pro Metal Detector is a highly versatile device that is capable of doing a good job of finding things.

Its 15kHz operating frequency is considerably higher than several VLF detectors in its price range.

It comes with two audio modes: pro and standard.

Both of these modes can be used along with the search modes on the detector.

What We Did Not Like:

One of the biggest issues that this metal detector faces is its headset.

The headset either stops working after a while of use or has some issues to begin with.


✔ Easy to use

✔ Lightweight

✔ Iron audio and notch discrimination to avoid any junk

✔ Can be fully submerged


Issues with the headset

Has no backlight

The second metal detector we will be reviewing is another one from the company Garrett.

This model is as good as the previous one we reviewed, but it comes with certain features that make it unique.

This metal detector can expertly eliminate any trash while still being able to locate precious metal underwater, thanks to its fantastic Discrete Trash Elimination mode.

Product Highlights

The Garrett Sea Hunter Mark II is an excellent metal detector for scuba diving, beach hunting, and snorkeling.

It is durable and has a cutting-edge waterproof design that makes it ideal for both saltwater and freshwater hunting.

As mentioned earlier, this metal detector comes with the groundbreaking and patented technology called the Discrete Trash Elimination mode.

This mode will expertly eliminate pull-tabs while still targeting any smaller valuables with a similar frequency.

This is a top-notch submersible metal detector that offers a full-range Pulse Induction discrimination.

Its salt elimination also allows the detector to be completely unaffected by the ground minerals and wet salt.

It is highly sensitive to most precious metals and can comfortably operate at depths going down to 200 feet.

If that’s not enough, this rugged metal detector also features an All-Metal Deep-Seeking mode, and Sensitivity/Depth adjustment.

Furthermore, the metal detector comes equipped with an eight-inch PROformance submersible search coil and the company’s submersible headphones.

What We Like:

The Garrett Sea Hunter Mark II is an excellent and must-have metal detector if you are looking to use one underwater, regardless of whether it is saltwater or freshwater.

It can detect at depths as deep as 200 feet, and, thanks to its state-of-the-art Discrete Trash Elimination mode, it will only target valuable items and keep the trash at bay.

What We Did Not Like:

Unfortunately, just like the previous Garrett Metal Detector we tried, this metal detector also has issues with its headset.


✔ Has an excellent battery life

✔ Highly durable and completely waterproof up to 200 feet

✔ Great price point


✘ Issues with headset

White’s Electronics is a family-owned company that manufactures some of the best metal detectors for security and recreation.

The company is known for taking advantage of the latest in research and development in the field of metal detectors and incorporating them in their wide range of products.

The Whites TDI BeachHunter Metal Detector comes with fantastic features that make it able to offer a deep detection.

Product Highlights

The Whites TDI BeachHunter is an excellent metal detector. It comes with a 12-inch dual field search coil, hip and chest mount pouch, and a pair of waterproof headphones.

This is built specifically for both the goldfields and the beach as it offers extreme depth performance both on sea and land.

It is waterproof up to 25 feet and can punch deep at the goldfields, beach, and even tough areas like red clay.

Its adjustable pulse delay allows you to set up the machine for maximum sensitivity to small nuggets, gold jewelry, and hammered coins at depth.

The machine weighs just 5.2 pounds, and with the hip and chest mount pouch, the user can customize it as per his hunting style.

The package includes heavy-duty NiMH rechargeable batteries that extend the detector’s run time to roughly six hours.

What’s more, the backup eight AA battery pack means that you are already set up for long days of searching relics, silver, or gold.

What We Like:

There are quite a few things that we liked about the Whites TDI BeachHunter Metal Detector.

For starters, its dual-field search coil provides sensitivity to both small and large targets without compromising depth.

Furthermore, it is lightweight and comes with a hip and chest mount that allows every user to adapt the platform to best fit his comfort levels and detecting styles.

What We Did Not Like:

Unlike many metal detectors that can run for 35 hours in one go, this model works only up to six hours.

This is mainly because it is a high-performing pulse induction metal detector.



Completely submersible

Excellent pulse induction

Features a dual-field search coil


Average battery life 

Fisher is a highly trusted name in the metal detection field. It was founded back in 1931.

Their wide range of metal detectors is ideal if you are trying to locate buried utilities, buried treasure, or more.

The Fisher 1280X-8 Underwater All-Purpose Metal Detector is an excellent machine with some interesting features.

Product Highlights

The Fisher 1280X-8 is an incredible metal detector built for use in shallow waters and lakes for activities like surfing, beach hunting, and diving.

It features a collapsible pole assembly design, which makes it easy to travel around with.

There are many features loaded in this machine.

For starters, it functions phenomenally well underwater. You can use it comfortably in saltwater and freshwater.

It can be easily used in water up to 250 feet of depth, too.

The use of the machine is fairly simple and straightforward in that it does not need any threshold adjustments, fine-tuning, or ground balancing.

This is designed with an easy-to-adjust sensitivity control and a turn-on-and-go type of operation that changes according to the conditions in which it operates.

What We Like:

The best thing about the Fisher 1280X-8 Underwater All-Purpose Metal Detector is how simple it is to use.

With very limited things to set, you can turn on the machine, and you are good to go.

It features a phenomenal battery life, too. We also like that its pole is collapsible, as this makes it easy to transport it.

Lastly, there are two choices of coils, and both of them are highly effective and work well.

What We Did Not Like:

We found the overall build of this metal detector to be just average.

As such, we feel that the manufacturer should put more thought into its overall construction.



Phenomenal battery life

Collapsible pole

Easy to use and straightforward functions


✘ Overall average build

Buyer’s Guide

We are certain that these five underwater metal detectors we have reviewed have certainly got you interested in pursuing your metal detecting journey.

Each of these is from reputed brands and is known to offer great functionality.

If you are still not sure which one you should choose among them, we recommend checking out our buyer’s guide so that you can make an informed decision.

1. Waterproof, Water-Resistant, or Submersible 

With underwater metal detectors, you know that the coil is definitely waterproof and can be submerged in water.

However, the same cannot be said for the remainder of the metal detector; we are mainly talking about the control box.

If the control box gets wet or is submerged in water, there is a high risk of the machine getting permanently damaged. Sadly, even the warranty don’t always cover this.

If you are primarily going to hunt underwater, we recommend looking for a completely submersible metal detector.

After deciding that you have chosen a fully submersible metal detector, there is yet another aspect that you will need to consider, and that is how deep can the metal detector go.

You will notice that every submersible metal detector is rated by depth.

For instance, some underwater metal detectors will state that they have a maximum submersion of five feet.

Depending on how deep you intend to go down, you should look for one that perfectly fits your needs.

You will find that the most common maximum depth of underwater metal detectors is 10 feet; some can go even deeper but will be more expensive.

Lastly, another factor to pay close attention to is whether the potential underwater metal detector can be used in freshwater or saltwater or both.

We recommend that you choose an underwater metal detector that works in both types of water.

2. Price 

The price of a metal detector is an important aspect that you must consider before purchasing one.

It is important to note that not every expensive metal detector is of great quality.

What you need to pay close attention to is its features and also note what exactly you are looking for.

That said, potential buyers should not sacrifice on the quality of the metal detector for affordability.

Make sure that the sensor you are selecting functions the way it should and is priced reasonably.

3. Coil Size 

A metal detector’s coil size is another aspect that is constantly overlooked.

Below, we will discuss large coils and small coils.

Large Coils

These coils will undoubtedly offer you a far better depth and significantly greater sweep area, which means that you will be able to cover more ground faster.

However, a metal detector with a large coil does have its downsides, the major one being all that extra weight.

You will often notice that when you change the coil of a metal detector from a smaller one to a larger one, there is a sudden and dramatic increase in its weight.

Every manufacturer will design the detector to be well-balanced with the stock coil, which means that the weight is distributed evenly.

When this is switched with a larger coil, the entire weight balance goes for a toss, and you will instantly feel the force of the larger coil pulling the detector down.

While you may be able to handle the weight, this poses a problem in the long run; when used for extended periods, you will get tired quickly. 

A larger coil also means that you will feel more surface tension/resistance when you swing the detector back and forth in the water.

Small Coils

Smaller coils are easier to handle and offer more accurate pinpointing, which is crucial since you cannot see the ocean floor.

Small coils are also ideal for beach hunting, where the beach has a lot of trash and target separation is an important factor.

However, a small coil means the area you cover is smaller; thus, you end up spending more time.

4. Headphones 

Since you will be using the metal detector underwater, the headphones must be of great quality and waterproof.

It should have noise-canceling features, as well, because you would not want to constantly hear the wind and the crashing waves.

Best Underwater Metal Detectors FAQs

1. Can you use a land detector underwater or in shallow river banks? 

No, you cannot use a land metal detector even in shallow river banks.

Unless it features a waterproof coil, then perhaps you can use it for shallow river banks.

Land metal detectors are not waterproof, though, so you must ensure that the control box does not get wet at any cost.

If you’re looking specifically to metal detect on the beach, then invest in the best metal detector for the beach.

2. Where can I use an underwater metal detector? 

There are some popular places where you can use your metal detector, such as along the shore of a beach or while wading or diving in waters that are up to your waist level.

If you know how to scuba dive, you can take advantage of your metal detector completely underwater to look for buried items in shipwrecks or other sites of interest.

3. What is the best time to metal detect underwater? 

It is extremely important to note that you should metal detect underwater only during the day.

Nighttime metal detecting is not only unsafe but also extremely challenging.

Metal detecting underwater during the day will give you better clarity and visibility.

You can always start early in the morning so that you can search all day long.

4. How to metal detect underwater? 

When metal detecting underwater, make sure that you’re being methodical with your search.

A popular method that many detectorists use is following an imaginary line and moving along it with about four to six feet swipes.

What Can You Find With Underwater Metal Detectors?

Wherever people gather they lose things! People gather on beaches they lie on the sand and things fall out of their pocket and get buried by sand quickly.

The most common item of ‘treasure’ to be found will be coins. In beach environment these are most likely to be present day coins, old silver or gold coins will be an exceptional find on a beach.

Folks also swim in the ocean and a mixture of sunscreen and the cool water causing finger shrinkage means that rings can often slip off and be lost. Until found by you!

Of course, if the ring has any identifying marks that may identify their owner such as a name then all efforts should be made to return the ring to its rightful owner. However, in practice this is going to be rarely possible.

Underwater Metal Detecting Accessories

In addition to your detector there are a few basic accessories you should have.


These are essential to filter out background noise and hear the subtle signals that may otherwise be drowned out by ambient noise. Most detectors will come with a standard set of headphones, but of course you might want to upgrade from the basic set.


You’ll need something to dig the sand around your target in order to locate your find.

Sand Scoop

A sand scoop will greatly assist you locate your discovery and speed up the process. A sand scoop is a simple sieve, fine enough to allow sand to pass but coarse enough to securely hold on to your find.


A simple pouch or utility belt is a useful accessory to hold your finds. You’d probably rather not fill your pockets with sandy finds.

Rechargeable Batteries

There’s nothing worse than your batteries running out of charge halfway through your session. Remember to carry some fully charged spares.


A pinpointer is an optional extra. Some people prefer them others prefer the sand scoop method. You’ll certainly need a pin pointer when treasure hunting in soil so you may already own one. But for beach and ocean hunting a sand scoop is quicker and just as effective.

Metal Detector Bag or Cover

Since you’ll have several items it makes sense to also purchase a metal detector bag or cover. This will keep all your things together and keep them protected.