Underwater Metal Detector: Diver’s Buying Guide

*This post may contain affiliate links. As an Amazon Associate we earn from qualifying purchases.

If you are an aquatic activities enthusiast, then you may enjoy underwater treasure hunting. There is something magical about exploring the depths of the ocean or lake, and advancements in metal detector technology has taken this to the next level. How cool would it be to find ancient antique objects, or even modern devices that have been lost to the waves?

Nowadays that is possible for an ordinary hobbyist. No matter what other avenues of diving you have enjoyed, such as spearfishing or photography, you can find a new hobby using an underwater metal detector to treasure hunt!

What Is an Underwater Metal Detector?

When a metal detector locates a metal object it either emits a sound or uses a moving needle on an indicator to show the proximity of the metal. Metal detectors are usually a handheld unit with a sensor probe. They can be swept over the ground or other objects to pick up metal signals.An underwater metal detector is a waterproof metal detector made for use beneath the water’s surface. There are two main types of underwater metal detectors: Pulse Induction (PI) metal detectors and Very Low Frequency (VLF) metal detectors.

Pulse Induction (PI) Metal Detectors

Pulse Induction metal detectors work by emitting a series of quick electronic pulses to the ground. They are highly sensitive to precious metals, but are not affected by ground minerals and wet sand. This makes them ideal for underwater treasure hunting.

The Pulse Induction metal detectors are best for diving and saltwater beaches. The Pulse circuit is great for tough ground mineral conditions because it is deep-seeking. However, the PI circuit has limited discrimination capabilities, so you will have to remove trash items to locate the maximum number of metal objects.

Some models of the Pulse Induction metal detectors include:

[amazon box= “B00HHIRU6U,B000CPMOYI,B0753SYGKP,B000G2NGTO,B00L5SL2H6″ template=”table”]

Very Low Frequency (VLF) Metal Detectors

Very Low Frequency metal detectors typically work in the 3 to 30 kHz (kilohertz) electromagnetic frequency range and are sensitive to relics, jewelry, and coins. Unlike the Pulse Induction metal detectors, Very Low Frequency metal detectors can discriminate trash items while still accepting good items.

However, they are affected by ground sensitivity. The signals caused by ground minerals can be minimized by adjusting the ground balance adjustment control or the sensitivity of the metal detector. Some models of the Very Low Frequency Metal Detectors include:

[amazon box= “B006J61ZKS,B000EVG8U6,B017URC5XK,B06WVCQWCW,B001LT9T5Q” template=”table”]

Which Metal Detector Is Best For Me?

Once you select the underwater metal detector that is best suited for your personal needs, you can begin treasure hunting. There are several factors to consider when choosing which type of underwater metal detector best fits your interests.

Type of water – If you will be hunting in fresh water, then the VLF metal detector is the best option for you. If you will be hunting in salt water, then the PI metal detector is the best option. However, some VLF metal detectors are equipped with a salt water mode and can be used in both fresh and salt water.

Depth Rating The depth rating of a metal detector measures how deep under the water you can use it. If you are diving, you need to consider how deep your depths will be and choose a metal detector that is appropriate. If you are diving or snorkeling, then make sure that whichever metal detector you choose comes with a short dive pole. This will make it more comfortable to use.

What is it Used For?

Underwater metal detectors are typically used by recreational divers for treasure hunting under the water. They can be used to find relics, jewelry, precious metals, and coins. There are several specific uses for underwater metal detectors:

Snorkeling – Underwater metal detectors can be used to treasure hunt with a diving mask and snorkel in fresh or salt water that is less than six feet deep. They can also be used for wading in a river or lake and surf wading.

Shipwreck Diving – Shipwreck diving involves using underwater metal detectors to find valuable artifacts inside sunken ships and treasure hunting around the area of the ship. It can be done in both shallow water and deep water up to a depth of 200 feet.

Scuba Detecting – Scuba detecting is detecting metal in salt and fresh water that is usually less than 20 feet deep. You use scuba gear for this type of detecting and may need additional training before attempting this method of underwater metal detecting.

Where Is It Used?

Underwater metal detectors can be used pretty much anywhere there is water. They can be used in closed water locations, such as lakes and ponds, or open water, such as beaches, oceans, and bays. They can be used in both salt and fresh water and in shallow or deep water.

You typically want to treasure hunt with your metal detector in frequently visited locations, such as popular beaches, lakes, and rivers. Docks, piers, and swimming holes are also good places to use it. The likelihood of someone dropping valuable items for you to find is much more likely.

How to Use An Underwater Metal Detector

There is a typical method that treasure hunters use when using an underwater metal detector. When using an underwater metal detector, the basic technique is to visualize a straight line or to set up a straight line using rope and sand screws along the bottom of the body of water you are treasure hunting in. You then move your metal detector back and forth in a sweeping motion over this line about five to six feet per side.

There are often “pot holes” in the sand on the bottom of the water, so you want to make sure you run your metal detector along those and dig for any finds that could be hidden there. These pot holes can prove to be surprise areas of bounty. If you are in sand that is less than five inches deep, then swing the search coil in front of you in a semi-circular motion at a moderate speed.

You want to overlap slightly. If you are in deeper sand, you want to slow down your sweeps and listen for deep and small signals. As you use these methods, you can find your targets much more efficiently and easy. There are also several accessories to use with your underwater metal detector to make your hunt a true success.

Underwater Metal Detector Accessories

Underwater metal detectors can be used alone or with accessories. Accessories help to make treasure hunts more efficient and successful.

Trowel – Trowels help to dig through heavy, difficult soil and cut through roots that may be in the sand. They can also make digging up treasures from pot holes or deep grooves easier.

Dive pole – A dive pole helps to reach greater depths and makes deeper diving more comfortable.

Waterproof headphones – Waterproof headphones help to block external noises and hear the deepest, oldest targets.

Carry bag – Carry bags make transporting your metal detector easier and protect them from damage when not in use.

Metal Detector Sand Scoop and Sifter – A sand scoop and sifter is a two-in-one metal detector accessory that increases the amount of sand you can search through at one time and effortlessly sieves the scooped amount, making finding detected metals easier.

Tips & Tricks

Now that you have all of your equipment and know how to use it, there are some useful tips and tricks for treasure hunting with an underwater metal detector that will help your trips even more fun.

Treasure Hunt in the Best Season

The best time to go treasure hunting is in the summer because you will be able to stay underwater longer since the water is warmer. There are many more tourists who will leave more valuable items behind for you to find.

If you do go treasure hunting in the winter, be sure to wear a wetsuit to protect yourself from cold temperatures. You always want to center your trips around the best weather and seasons.

Treasure Hunt at the Best Time

Daytime hunting is the safest and easiest type of hunting. This is because nighttime hunting can make it very difficult to see under the water. Nighttime hunting can also be dangerous because of snakes and other creatures that come out at night.

Know the Water Current

If you want to find targets easily and quickly, then it is best to know the current under the water. This current will show you the direction the sand is moving, giving you a good indication of where metals may be stuck.


Whether you are an advanced diver or a novice, underwater treasure hunting can be an exciting new hobby for you. We hope our article has given you all the information you need to get started. By using an underwater metal detector, you will be able to find valuable objects and expand the horizons of your subaquatic expeditions.

Featured image by John Cahil Rom via Pexels.

Jack Thompson

Jack Thompson, a scuba diving enthusiast from San Diego, has spent over a decade exploring the underwater world across the globe. Sharing his passion through captivating stories and informative articles, Jack aims to inspire others to embark on their own scuba diving adventures and uncover the ocean's hidden treasures. Follow Jack on Twitter, Pinterest, Reddit, and Facebook or email him at Jack@diving-info.com

Leave a Reply

Your email address will not be published. Required fields are marked *

Recent Posts