I’ve been diving for more than 40 years and still get a kick out of it.
I particularly enjoy spearfishing and have shot a lot of game fish. But unfortunately, there’s so many fish you can eat.
So awhile back, my buddy recommended a metal detector, and I got one for myself, and honestly, this has changed my entire scuba experience.
While scuba diving in itself is enthralling, taking a detector to a site you’ve dived dozens of times adds a new dimension to the experience.
Even divers that have “done it all,”; underwater photography, spearfishing, rebreathers, etc, are still awed by the thrill of discovering treasure with a detector.
See, there’s no greater feeling than digging up a rare treasure on a ground most detectorists can’t access or even have the tools for the task.
The satisfaction of finding something valuable in the remotest environments is unimaginable.
And the good thing with underwater treasure hunting is it doesn’t take a gold bar to get the adrenaline pumping. Instead, any discovery, regardless of its value, feels like a real treasure. It’s like an Easter Egg hunt!
Secondly, there’s a world of undiscovered treasure lying on the sea bed or river bed that you can easily access with the right tools.
For me, I prefer the “party coves” or rather where folks go-to drink and swim. Here, it’s easier to find all kinds of stuff, including coins, watches, jewelry, sunglasses, and more.
The only problem that comes with hunting underwater is it’s just as challenging, if not more, as hunting on the surface.
To hunt underwater, you need a fully waterproof metal detector. While some claim to be waterproof, this often means only the search coil survives in shallow depths.
For a metal detector to work when fully submerged, all electronics components should be sealed and tested.
Now, whether you’re planning to hunt in the sea, beach, ocean, or local river, here’s a review of the best underwater metal detectors.
Table of Contents
Quick Comparison Table!
The Best Underwater Metal Detectors For The Money
#1 Garrett AT MAX - EDITOR'S CHOICE
- Quality
- Price
- Our Rating
Our review of the best underwater metal detectors can never be complete without Garrett.
Garret has been around for the longest time and has a reputation for developing reliable and quality treasure hunting products.
And today, we will look at one of its most successful detectors, the Garret AT Max, a device that offers both land and underwater searching capabilities.
AT Max is a follow-up to the AT Pro. While it’s not designed to replace the AT Pro, it adds several new features for detectorists who want more from their machine- and don’t mind spending extra.
Features and Benefits
Design
AT Max is the latest detector in Garret’s popular “All-Terrain” series.
How does it perform in the field?
As its name suggests, this option is a versatile device tailored for serious hunting. It’s suitable for almost any environment and offers great depth for both land and shallow-water detecting.
It’s hardy, too, and will take a beating during transit and hunting on rough terrain.
Depth
The AT Max is fully submersible down to 10 feet.
While you won’t take the Max scuba diving with you, it’s a great option for hunting in streams, shorelines, and anywhere with shallow waters.
Z-Lynk Wireless Technology
AT Max’s claim to fame is the Z-Lynk integrated wireless technology with wireless headphones.
I’m a big fan of this feature as it suffers from less interference and faster transmission than Bluetooth, so you get the benefits of cordless audio without the downsides.
There’re not audio delays when the search coil is above the target, and this is a crucial feature to have as the slightest delay would make it troublesome in pinpointing the potential targets.
Z-Lynk also rids the audio cords’ inconvenience, and detectorists will love that they don’t have to be chained to the detector.
13.6kHz Operating Frequency
AT Max has the lowest operating frequency of the AT series, operating at only 13.6kHz.
Nonetheless, it’s still higher than the average VLF detectors.
I find the frequency ideal for all sorts of targets, including coins, relics, and jewelry.
While it’s sensitive enough to pick up gold nuggets, it’s not ideal for gold hunting. You would be better off with the AT Gold for gold prospecting.
One of the biggest observations of the AT Max is that it’s a single-frequency device. While I can subtly adjust the frequency to eliminate interference from other detectors, I can’t change it so not ideal for highly mineralized grounds.
The good news is, it’s not an issue for AT Max alone but all VFL detectors.
True All-Metal Mode
A true all-metal mode offers maximum depth and sensitivity.
It’s a critical feature for deep searching detecting- a must feature for the serious relic hunters.
This feature is not available in the AT Pro but is part of the AT Gold.
Adjustable Ground Balance
I’ve no problem using the AT Max in shallow river depths or the saltwater beaches, thanks to the manual and automatic ground balance.
The detector is not affected in the heavily mineralized conditions as well as saltwater beaches.
Even better, detectorists can alter the ground balancing in quarter-point increments.
Digital Target ID
Beginners will have an easy time operating the AT Max because they’re identified on the LCD panel once they close on their target.
The readings range from 0 to 99 while offering a visual representation of the target’s composition.
While the digital display is standard among many mid-level detectors, AT Max provides all the information quickly and accurately.
Pros
- Can be used on both land and in water
- Adjustable ground balance (Not affected by saltwater or mineralized grounds)
- Fast and accurate display of target
- True mode for maximum depth
Cons
- Not ideal for gold hunting
#2 Garrett AT Pro Metal Detector - Best All-Around Underwater Detector
- Quality
- Price
- Our Rating
Looking for an all-around underground metal detector at an affordable price tag?
You can’t go wrong with the AT Pro.
The Pro is yet another wonderful detector from Garret, specifically from Garrets AT line as the AT Max we reviewed earlier.
But how does it perform?
Features and Benefits
Waterproof, all-terrain capabilities
If you’ve any desire to hunt in or near a water source, you should take a closer look at this option.
Why?
The AT Pro is waterproof and submersible to 10 feet of water depth, making it ideal for hunting around lakes, creeks, rivers, ponds, and the ocean.
It’s a unique feature to have, considering that many detectors only come with a waterproof coil and aren’t entirely submersible.
Still, the AT Pro isn’t a great option for deep diving or treasure hunting shipwrecks.
Pro Audio Mode
Digging up trash when a detector says it is silver or gold happens more often than you imagine.
Fortunately, AT Pro eliminates that with the push of a button.
With the pro audio mode activated, the detector emits more than a single tone over a target, representing its characteristics, including shape, conductivity, depth, and type. This way you can easily identify a target even before digging it up.
While identifying the tones has a learning curve, detectorists appreciate the feature as it lets them dig more treasure and less trash.
Iron Mode
As with the Pro model, the iron mode is another sophisticated feature not found in the entry-level Garret ACE series.
When activated, it lets you determine whether there’s iron or ferrous material in the ground and is likely trash unless you’re relic hunting for iron targets.
It’s a useful feature for all types of treasure hunters but particularly handy for coin shooters.
Coin shooters will hunt with the iron mode notched out. When they hit a questionable target, they can’t decide whether to dig; they activate the iron audio and instantly determine if any iron exists in the target.
15kHz Operating Frequency
The AT Pro operates at 15kHz. It’s slightly higher than the AT Max, though a bit lower than AT Gold.
AT Pro’s frequency has numerous benefits, including picking up tiny targets and better target separation.
It also makes the detector more qualified for picking gold nuggets.
Ground Balance
AT Pro won’t limit you to where you can take your treasure hunting.
It has both manual and automatic ground balancing capabilities, allowing the detector to ignore iron and salt signals.
It’s a great option for use in the saltwater or beaches since it cuts down on ground signals’ chatter while letting you find targets at deeper depths and with better accuracy.
Observation with the AT Pro is that it’s a single-frequency detector, as with most detectors at this price range.
So, regardless of the ground balance feature, you might encounter some challenges when treasure hunting in high mineralized locations.
Pros
- All-terrain use
- Higher operating frequency for gold detection
- Suitable for coin shooters
Cons
- Single-frequency detector
#3 Garrett Sea Hunter Mark II - Best for Diving
- Quality
- Price
- Our Rating
If you’re after treasures buried deep under wet sand or at the bottom of the seabed, you can’t go wrong with this option.
Even better, the detector boasts of a Pulse Induction technology that goes deeper than the traditional VFL.
While it’s a bit pricey than most VFLs, the extra pay does a lot more than you ever hope for.
Features and Benefits
Pulse Induction Technology
Pulse induction technology is among the finest metal technologies, thanks to its deep soil penetration and ability to detect the tiniest targets in highly mineralized environments.
Unfortunately, the PI technology runs cold for some of the detectorists.
While it has deeper soil penetration, its high sensitivity makes it challenging to acquire metal differentiation and is vulnerable to varying signal interference types.
Nevertheless, the benefits far outweigh the flaws, and in this case, if you’re treasure hunting for gold or other valuable in high-slat areas and underwater, the Sea Hunter performs well.
Discrete Trash Elimination
PI detectors have a problem discriminating against different metals.
But the issue with using a discrimination mode is the decrease of depth and sensitivity.
Fortunately, Garret has broken grounds with the discrete trash elimination mode, eliminating trash and picking the smaller treasures.
Depth
Detectorists who like to take their hunting to the depths of the sea, including the sea bed, will delight in the Sea Hunter.
Why?
It’s fully submersible and has a decent depth of 200 feet underwater. You can take it for snorkeling or deep diving.
Combine with the enhanced discrimination mode, and you get a detector that can exclude trash from detection and find buried treasures without virtually missing a treasure.
Frequency
The Sea Hunter is set as 7.2 kHz, though the state-of-the-art PI technology allows it to alternate between 22 frequencies.
Detectorists can manually adjust the frequencies to fine-tune the detector for the best depth and sensitivity trade-offs for your hunting area and goal target.
This makes the Sea Hunter a better candidate for treasure hunting even in saltwater and high mineralized locations.
Audio
The absence of a digital target display isn’t a deal-breaker, considering it’s always challenging to the reduced visibility conditions of brackish waters.
Instead, you’ll have to rely on an audio tone on the Sea Hunter.
The tones are based on a threshold between 1 to 10 and are controllable by the detector’s second dial.
Pros
- Pulse Induction technology
- Greater depths
- Ideal for diving
Cons
- Runs a bit expensive
#4 Fisher 1280-X Aquanaut Metal Detector - Easy to Use
- Quality
- Price
- Our Rating
Fourth on our list of the best underwater metal detectors may intrigue beginners.
Fisher Aquanaut is a mid-level metal detector best known for its simple design and ease of use.
However, its modesty isn’t at the expense of performance because it works well as any other premium device.
Features and Benefits
Ready-to-Go
Beginners idolize the Fisher Aquanaut because of its modesty.
It’s a ready-to-go device that doesn’t require ground adjustment, fine-tuning, or threshold tune.
Using the detector is as simple as switching it on, configuring the sensitivity, trash discrimination, and volume.
The detector does all the hard work, including fine-tuning and adjusting ground conditions and saltwater settings- a novice’s delight.
Design
If you thought the Sea Hunter has the highest depth, you’re mistaken.
This is because Fisher Aquanaut offers a generous depth of 250 feet, 50 feet more than the Sea Hunter.
It’s the perfect purchase for detectorists who need to take their treasure-hunting the depths of the sea bed and rivers.
To put it bluntly, this device was created with one of the most durable enclosures that can withstand deep-water pressure.
2 Search Modes
Fisher Aquanaut has a unique detection method as it features two search modes: slow-motion and VLF-IB.
VLF-IB operates at a frequency of 2.4kHz, which is fantastic for finding small targets.
But given the device is a motion detector, you’ll need to keep the device in motion to pick up a target.
Accurate Pinpointing
In contrast, accurate pinpointing requires you to keep your coil still.
While it requires some elbow grease to use the Fisher Aquanaut’s pinpointing, the results are worth it.
However, the manufacturer recommends maintaining a 2 ft distance of search coil from their bodies to prevent interference.
Additionally, the detector lacks dual-ground balancing features to false-signal in the salt waters or the highly mineralized grounds.
Ease of Use
One more thing beginners will love about this detector is its ease of use and convenience.
Fisher Aquanaut comes complete with a hip mount, which reduces the weight on land and deep water.
It also gives users the option of detaching the control box to reduce the equipment’s weight even further.
Pros
- Easy to use
- Perfect for beginners
- Greater depth
Cons
- Sensitive to digging tools or body
#5 Minelab Excalibur II - Best for Professionals
- Quality
- Price
- Our Rating
Our final pick, Minelab Excalibur II, runs a bit expensive, but it ticks on all the right boxes for the best underwater detector for professionals.
It comes with a plethora of admirable features, but its claim to fame is the BBS technology.
Additionally, it’s perfect for use in a range of treasure hunting activities, including jewelry hunting, relic hunting, underwater hunting, and beach hunting.
Features and Benefits
BBS Technology
Minelab Excalibur II flaunts Minelab’s Broad Band Spectrum (BBS), allowing it to perform on multi-frequency channels.
The wide range of channels (1.5-25.5 kHz), 17 in particular, deliver considerable detection depth, sensitivity, and discrimination for all target types.
Detectorists can get more information about the potential target on a single-frequency technology because of such a huge frequency range.
Even better, the technology reduces the chatter while amplifying the signals that are small and in deep locations.
Submersible
As if being waterproof alone isn’t enough, Minelab goes all out and provides a completely submersible device for diving.
Minelab Excalibur II has a generous depth of 196 feet, so it’s perfect for use on the depths of the sea, including the seabed.
Even better, Minelab Excalibur II can also be used on land.
So, when you need to take your treasure hunting on land, you don’t have to opt for another quality detector since Minelab Excalibur II is a do-it-all.
Coil Boost
With BBS technology and adjustable frequency, you would think it would be more than enough technology to locate and target treasure.
Not with Minelab.
The brand has knocked the ball out of the park as far as the detection performance is concerned.
This is evident with the Receive Coil Boost (RCB) or simply cool boost.
You wonder what it does?
It does exactly what it sounds like- amplified the faint signals that would normally be too weak to hear or those that would be lost in the fray of disrupting noise.
The patented technology helps with depth detection and increases the sensitivity and ensures that you never have to pass a valuable target because you can’t hear the signal.
Smart Discrimination Functions
One of the challenges with detectors is they rarely differentiate between trash and treasure. In most cases, detectorists will find themselves digging up bottle caps or other trash.
But the Minelab Excalibur II, you don’t have to worry about that, thanks to the smart discrimination function.
The feature allows the detector to sort out valuables from the trash. This way, you’re unlikely to spend your time digging up trash.
Besides that, smart ground balancing prevents chatter and filters fake signals from the highly mineralized soils and salty waters.
All in all, ground balancing lets users operate the best in both salty and freshwater.
Pros
- Best for professionals
- Amplifies faint signals
- Generous depth
- Operates on multiple channels
Cons
- Expensive
Best Underwater Metal Detectors Buying Guide
Choosing an underwater metal detector is challenging, considering there’re numerous options and features to consider.
It doesn’t have to be that way, though.
I will share with you everything you need to know before selecting an underwater metal detector in the text below.
But before I do that, let’s look at the different types of underwater detectors;
Types of Underwater Detectors
Underwater detectors’ detection type generally falls into two categories; VLF (very low frequency) or PI (pulse induction).
PI
Pulse Induction detectors tend to be more expensive than the VFL.
They’re not sensitive to ground mineralization and are fantastic picks for saltwater use.
Unfortunately, they don’t do a good job of filtering out junk, so you may spend more time in unnecessary digging than you would with a VLF detector.
VLF
By contrast, VFL detectors don’t get as distracted by so-called background noise from junk.
While they may not be ideal for saltwater use, they may be better suited to finding jewelry and relics in freshwater than PI detectors.
Depth
Once you’ve identified the type of detection, the next factor is to consider the depth.
Depth is crucial, especially if you plan to dive.
Some models can work in deep waters, up to 250 feet below the surface. They’re ideal for detectorists who need to explore the shipwrecks or deep lacks.
Depths matters because if you take a metal detector too deep, it may cease to work.
The extreme pressure of the liquid above it can cause leaking of the product, ultimately damaging your detector.
In saltwater, extreme depth may cause corrosion, while the interior may get too sensitive to it.
If you’re serious about underwater metal detection, opt for the sturdiest device that will handle serious depth. This way, you’re less likely to get caught unaware or risk damaging your equipment on a dive.
Accuracy
Accuracy is yet another crucial element to consider.
Underwater detection has plenty of challenges, and one of them is your hunts may be buried deep in the sand or dirt.
And that’s not even the main challenge!
The movement of liquid can turn an object on the sea bottom into buried treasure quickly.
So, when choosing a metal detector, pick one with good depth perception and accuracy.
If you’ve experienced diving in certain areas, then you may have an idea of how deep you need to go to unearth the treasure.
Versatility
If you’ve a budget for more than one quality metal detector, you can skip this part and go to the next.
However, if you need a multi-purpose detector, keep on reading.
Some detectors are also good on land, while detectorists can use the premium picks on both freshwater and saltwater and land.
Weight
Underwater detectors are quite heavy, much heavier than regular detectors.
So, if you want to pick a multi-purpose option for land and water, ensure you choose the lightest.
You may also want to consider a chest strap to get off the weight on your arms while hunting.
Accessories
It’s important to consider the accessories that a metal detector comes with.
Since many of the underwater detectors are expensive, these little extras can make a difference in how you feel about paying a premium.
Some of the common accessories you should be on the lookout include waterproof headphones, carrying bags, straps, and instructional books.
Budget
Generally, underwater detectors are expensive, so you’ll have to figure out what you can afford. But keep in mind you get what you pay, so you might end up paying more for a cheap product.
Frequently Asked Questions (FAQs)
Q: Can metal detectors work underwater?
A: Yes. While most waterproof detectors cannot work underwater, the submersible or underwater detectors can.
The underwater detectors come with waterproof protection to the entire device, including the control box and headphones.
Q: How much do underwater detectors cost?
A: The price of water detectors varies significantly, and of course, brand.
However, most of the detectors from reputable brands will start at around $500-$700.
The more expensive models, offering greater depths, will run anywhere from $1,000.
Wrap Up: Our Choice
Few underwater detectors can beat the Garret AT Max.
This mid-level underwater detector ticks on all the best underwater detectors’ boxes and comes with some intriguing features.
I’m a big fan of the Z-Lynk technology that offers a no-lag and accurate target detection.
While the detector falls short on the target depth, it’s an awesome option, especially if you don’t plan to take your treasure hunting to the seabed.
