Best underwater metal detector: The ultimate buying guide for 2017

Everything you need to know before buying an underwater metal detector

Underwater metal detectors are waterproof. Plenty of metal detectors have waterproof search coils, but you can’t immerse the control box in water. This means they are only good for shallow water detecting. Some models are only to be used in fresh water. A saltwater metal detector can be used in sea water or fresh water.

Some waterproof metal detectors will allow you to search in water up to ten feet (three metres) deep. But the best waterproof metal detector will allow you to submerge the unit to a depth of up to 200 feet.

You can also use an underwater metal detector on land – they work just as well on land as the non-waterproof models.

If underwater treasure hunting is something you want to get serious about, and whether you’re upgrading or buying your very first detector, you’ll find a lot of great information about the features of each. This will help make it easier to decide which model to buy.

Our review of the best underwater metal detectors will take you through a range of VLF and PI metal detectors to suit your needs and budget.

Best underwater metal detector

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A comparison of underwater metal detectors

Make

Model

Price

Type of metal detector

Salt water compatible

Fresh water compatible

Suitable for scuba diving

Depth rating

Weight

Search coil

Battery life

Waterproof headphones 

Warranty

Manufactured

Tesoro

Tiger Shark

$$

VLF 12.5 kHz

200 feet (66m)

4.5 lbs

10.5"

Up to 20 hours

Lifetime

USA

Tesoro

Sand Shark

$$

PI 600 pps

200 feet (66m)

4.5 lbs

8" or 10.5"

Up to 20 hours

Lifetime

USA

Minelab

Excalibur II

$$$

VLF 1.5kHz – 25.5kHz

200 feet (66m)

5.1 lbs

10"

Up to 12 hours

1 year

Malaysia

Minelab

CTX 3030

$$$$

VLF 3.125 kHz - 25.0 kHz

10 feet (3)

6 lbs

11"

Up to 13 hours

3 year

Malaysia

Garrett

ATP Pro

$$

VLF 15kHz

10 feet (3m)

3 lbs

8"

Up to 40 hours

2 years

USA

Garrett

Sea Hunter Mark II

$$

P

200 feet (66m)

4 lbs

8"

Up to 22 hours

1 year

USA

 

Underwater metal detector 101

Features to consider before buying an underwater metal detector

When buying your underwater metal detector, there are plenty of things to consider, from the environment you’ll be searching in to the features you’ll need to suit the type of underwater metal detecting you want to do, to how much you’re willing to spend. You’ll also need to consider whether you need a scuba diving metal detector or one for hunting only in the shallows.

1.   Type of metal detector

There are two types of metal detectors:

  • Pulse Induction (PI) – this kind is best for salt water treasure hunting
  • Very Low Frequency (VLF) – make sure it has a salt water mode
Pulse Induction metal detectors

PI metal detectors are the best for salt water environments and scuba diving.

PI metal detectors work by sending short bursts of electronic pulses into the ground. They are highly sensitive to precious metals and unlike VLF detectors, they’re not affected by mineralized soil or sand.

The downside of PI detectors is that they can’t be set to ignore iron – they operate in an ‘all metal’ mode. But as you’ll see from our reviews below, some PI models are better at discriminating between junk metals and iron, and precious metals.

The best underwater PI metal detectors and reviewed here are:

Very Low-Frequency Metal Detectors

VLF detectors operate in the 3-70 kHz frequency, but more commonly in the 3-30 kHz frequency. They are highly sensitive towards metallic targets like jewellery, coins, silver and metal artifacts.

Because of their high sensitivity, a good VLF metal detector will separate junk metals from target metals once you’ve adjusted the ground balance to prevent interference from mineralized soil. Your metal detector needs to suit your environment.

The best underwater VLF metal detectors and reviewed here are:

2.     Salt water vs fresh water detecting

Consider the environment where you’ll be using your metal detector. Some metal detectors are better suited to fresh water while others are designed for salt water. All waterproof metal detectors can be used on land.

Sea water presents unique problems for metal detecting. Most detectors are unusable in a salt water environment, so you’ll need a VLF model suited for salt water or a PI type. A salt water metal detector is what you want for shallow beach hunting or SCUBA diving.

3.     Depth rating

Some waterproof metal detector models are only waterproof to 10 feet (three meters), which is fine for shallow reefs and the beach, but if you want to go scuba diving deeper than 10 feet, you’ll want to choose a model with a higher depth rating.

4.     Waterproof headphones

It can get noisy under the ocean so you’ll want to invest in a pair of quality underwater headphones, or buy an underwater metal detector kit that comes with waterproof headphones. We’ve highlighted the models that come with waterproof headphones.

5.     Weight and buoyancy

You’ll want a metal detector that isn’t so heavy it’ll make you sink in water, but you don’t want one that will keep you floating towards the surface. You’ll want an underwater metal detector with neutral buoyancy (or as close to near neutral as possible). You’ll also want one that’s fairly lightweight because you’ll be swinging that cat around for hours.

6.     Search coil

A search coil is a kind of antenna built to transmit and receive signals. They’re usually tuned to work on specific detectors at specific frequencies. Consider whether you want an interchangeable search coil and what sort of targets the coil is best for. Most brand coils are interchangeable within the one brand, but not between brands. However, you can find aftermarket coils to suit your needs.

Let’s take a look at the best underwater metal detectors available today.

Underwater metal detector reviews

Tesoro Tiger Shark

Features of the Tesoro Tiger Shark

The Tesoro Tiger Shark is a dual function underwater metal detector. Scuba diving? No problem. It works equally as well on land or in water. In ‘normal’ mode, it used ground balance and discrimination features. In salt water, switch to ‘salt’ mode to tune out mineralization. This is what makes it a truly dual function metal detector.

For its price and with its lifetime warranty, we think this US designed and manufactured metal detector is well worth considering if you’re looking for a quality all-round device. See our full review of the Tiger Shark, including a comparison with the Garret AT Pro.

Price $$ – Click to check today’s price
Type of detector VLF 12.5 kHz
Suitable for salt water Yes
Suitable for fresh water Yes
Suitable for SCUBA diving Yes
Depth rating 200 feet (66m)
Weight 4.5 lbs
Search coil 10.5”
Battery life Up to 20 hours
Headphones included Yes, waterproof headphones
Warranty Lifetime warranty
Made USA

Best for

All levels of users

The Tesoro Tiger Shark is best for:

  • Underwater treasure hunting
  • Coin and relic hunting on land
  • Gold prospecting
  • Beach hunting

The pros

  • The price – packed full of features
  • Waterproof headphones are included
  • Lifetime warranty
  • Works equally well on land and in sea

The cons

  • We can’t think of any!

Click to check the price

Tesoro Sand Shark

Features of the Tesoro Sand Shark

The Tesoro Sand Shark is a microprocessor-controlled Pulse Induction (PI) metal detector. Many experienced treasure hunters agree that a PI metal detector is best for salt water and wet salt beach detecting because unlike a VLF model, you won’t see changes in salt water conductivity.

There isn’t much price difference between the Sand Shark and the Tiger Shark. If you’re buying the detector primarily for underwater metal detecting in salt water, then we recommend the Sand Shark over the Tiger Shark. If you’re looking for an all-terrain device, then got with the Tiger Shark. See our full review of the Sand Shark for more detail.

Price $$ – Click to check today’s price
Type of detector PI 600 pps
Suitable for salt water Yes
Suitable for fresh water Yes
Suitable for SCUBA diving Yes
Depth rating 200 feet (66m)
Weight 4.5 lbs
Search coil 8” or 10.5”
Battery life Up to 20 hours
Headphones included Yes, waterproof headphones hardwired into the control box
Warranty Lifetime warranty
Made USA

Best for

All levels of users

The Tesoro Sand Shark is best for:

  • Wet salt beach hunting
  • SCUBA diving and underwater metal detecting
  • Coin and relic hunting on dry land
  • Gold prospecting.

The pros

  • The price – you get bang for your buck
  • Waterproof headphones are included
  • Lifetime warranty
  • Brilliant in salt water

The cons

  • Again, we’re struggling with the cons of this model.

 

Click to check the price

Minelab Excalibur II

Features of the Minelab Excalibur II

The Minelab Excalibur II is a VLF metal detector that can move seamlessly from land to beach and wet sand conditions to underwater depths of up to 200 feet (66m).

When life is too short to spend digging six-inch holes for fish hooks, the Excalibur II will ignore iron and minerals so it doesn’t need to be ground balanced. This model also has really good resale value if you think you’ll want to upgrade or change in the future. Read our indepth review of the Excalibur II.

Price $$$ – Click to check today’s price
Type of detector VLF 1.5kHz – 25.5kHz
Suitable for salt water Yes
Suitable for fresh water Yes
Suitable for SCUBA diving Yes
Depth rating 200 feet (66m)
Weight 5.10 lbs
Search coil 10” or 8″ coil
Battery life Up to 12 hours
Headphones included Koss Non-waterproof headphones
Warranty 1 year control box and coil
Made Malaysia

Best for

Intermediate to Experienced Users

The Excalibur II is best for:

  • Coin and relic hunting
  • Jewellery hunting
  • Beach hunting
  • SCUBA diving and underwater metal detecting

The pros

  • Excellent resale value
  • Excellent discrimination

The cons

  • Limited warranty
  • Not made in the USA
  • Limited battery life

Click to check the price

Minelab CTX 3030

Features of the Minelab CTX 3030

The Minelab CTX 3030 is a VLF metal detector with a GPS feature that can navigate to your favorite locations. It also records your hunts – you can track your hunts and later look at your coverage trends and patterns to see how you could improve your searching. Unlike the Excalibur II, it is only waterproof to a depth of 10 feet.

This Minelab waterproof metal detector has a full-colour LCD and five pre-set modes. It’s the priciest model in this review, but you could earn back the cost with your finds. It misses very little if anything. The CTX 3030 is everything the Excalibur II is but more accurate. If SCUBA diving and deep water treasure hunting isn’t your thing, and if the price doesn’t scare you, this is a great detector. See our in-depth review of the CTX 3030 for more details. in-depth review of the CTX 3030 for more details.

Price $$$$ – Click to check today’s price
Type of detector VLF 3.125 kHz – 25.0 kHz
Suitable for salt water Yes
Suitable for fresh water Yes
Suitable for SCUBA diving No
Depth rating 10 feet (3m)
Weight 5.20 lbs
Search coil 11” coil
Battery life Up to 13 hours
Headphones included Koss Non-waterproof headphones
Warranty 3 year control box and coil
Made Malaysia

Best for

Intermediate to Experienced Users

The Minelab CTX 3030 is best for:

  • Coin, relic and artifact hunting
  • Underwater metal detecting
  • Jewelry hunting
  • Gold prospecting
  • Beach hunting

The pros

  • It has GPS functionality
  • Excellent discrimination
  • Excellent target identification

The cons

  • Not for SCUBA diving
  • Not made in the USA
  • Limited battery life

Click to check the price

Garrett AT Pro

Features of the Garrett AT Pro

The Garrett AT Pro is a VLF metal detector that’s at the lower end of the price range in this review of underwater metal detectors. The main negative of this device is that it’s only waterproof to 10 feet, making it not suitable for SCUBA diving.

This Garrett underwater metal detector is great for detecting coins. It’s lightweight and balanced, so it won’t tire your arm like heavier models. If you’re just getting into the treasure hunting hobby but not interested in diving, then this is a fantastic detector for the price. You’ll need to get used to the device, and this could take some patience and time, but well worth the investment.

The auto ground balance feature is a winner. You can read our full review of the Garrett AT Pro.

Price $$ – Click to check today’s price
Type of detector VLF 15kHz
Suitable for salt water Yes
Suitable for fresh water Yes
Suitable for SCUBA diving No
Depth rating 10 feet (3m)
Weight 3.03 lbs
Search coil 8.5”
Battery life Up to 40 hours
Headphones included Yes, non-waterproof headphones
Warranty 2 Year, Limited Parts/Labor
Made USA

Best for

Intermediate to Experienced Users

The Garrett AT Pro is best for:

  • Small gold nugget hunting
  • Coin, relic and artefact hunting
  • Beach hunting
  • Fresh water hunting.

The pros

  • Great all-round unit
  • Extremely lightweight
  • Automatic ground balancing
  • Excellent battery life

The cons

  • Only waterproof to 10 feet / 3 meters
  • No waterproof headphones included

Click to check the price

Garrett Sea Hunter Mark II

Features of the Garrett Sea Hunter MK II

The Garrett Sea Hunter MK II is a pulse induction underwater metal detector with a nose for eliminating most of the junk you’ll come across on land or underwater.  A few hundred dollars more than the Garret AT Pro, it’s still one of the more affordable metal detectors in this review.

If you’re not going to SCUBA dive with this unit, then the Garrett AT Pro might be a better choice for you.  You’ll also want to learn how to use it on land and then in shallow water before taking it diving. Check out our full review of the Garrett Sea Hunter Mark II.

Price $$ Click to check today’s price
Type of detector PI
Suitable for salt water Yes
Suitable for fresh water Yes
Suitable for SCUBA diving Yes
Depth rating 200 feet (66m)
Weight 6 lbs
Search coil 8” coil
Battery life Up to 22 hours
Headphones included Yes, non-waterproof headphones
Warranty 1 year limited
Made USA

Best for

Intermediate to Experienced Users

The Garrett Sea Hunter Mark 2 is best for:

  • Jewelry hunting
  • Coin and relic hunting
  • SCUBA diving and underwater metal detecting
  • Wet salt beach hunting

The pros

  • Excellent price point
  • Perfect for SCUBA diving and underwater metal detecting
  • Good battery life

The cons

  • Limited warranty
  • No waterproof headphones included

Click to check the price

Frequently asked questions (FAQs) about underwater metal detectors

Are metal detectors waterproof?

No, not all metal detectors are waterproof. Some come with a waterproof search coil but the control box is not waterproof, so you can only submerge the search coil and shaft of the metal detector in water. Waterproof metal detectors allow you to fully submerge the control box and are suitable for SCUBA diving and underwater metal detecting. Check their depth rating to see how deep you can submerge the metal detector.

Can you use waterproof metal detectors on land?

Any waterproof metal detector can be used on land. Pulse induction (PI) detectors aren’t affected by sea water, so these are a good choice for underwater metal detecting. PI detectors operate in an ‘all metal’ mode, so it’s harder for them to discriminate between junk iron and precious metal. Very low frequency (VLF) metal detectors that offer a salt water mode and discrimination will work well in water and on land.

Why is pulse induction better for salt water detecting?

Sea water is a unique environment and presents challenges for metal detecting. Because most detectors are unusable in a salt water environment,  you need a dual function VLF or a PI type of metal detector. PIs are the best for dealing with sea water because they aren’t affected by its conductivity and the mineralization of soil or sand, but you can still get VLF detectors with a salt water mode.

What sort of headphones do I need?

If you’re going to dive with a metal detector, then you need waterproof headphones. Some models, like the Tesoro Tiger Shark and Tesoro Sand Shark, come with built-in waterproof headphones.

If the model you want doesn’t come with waterproof headphones, then .

How important is the weight of an underwater metal detector?

An underwater metal detector will be lighter when compared to a standard metal detector. This is because you’ll be carrying the metal detector in the sea and if it’s too heavy, it would make you sink and be more difficult to control. If it’s too light and buoyant, it will be tiring to continually force the detector down, or it could easily float away if it’s unattached.

Are underwater metal detectors suitable for beginners?

Even experienced detectors will need some time to get used to a new metal detector before taking it underwater. A beginner should practice with the detector on land first and familiar themselves with the detector’s functions before taking it underwater.

The information in this post was sourced from the product manufacturers and our own experience. Please check product specifications before buying a metal detector. Some products come in kits and may contain different accessories and different sizes to what’s mentioned in this post.

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One Response

  1. Ralph Renteria November 18, 2017

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