Underwater Metal Detectors – A Beginner’s Guide To Digging Deep

Splish splash, metal detectors taking a bath! 🔍💦
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Metal detecting is an increasingly popular sport, which has been described as ‘going on an Easter Egg hunt’ all year through. If you change your search to coastal, river beaches and underwater, you will definitely increase the number of items you find! However, you’ll need to invest in a waterproof metal detector. People lose coins and jewellery regularly either in the sand or in the sea as they swim. One successful detectorist remarked that there is ‘probably more buried coins and jewellery on the beach and underwater than there is in circulation!

Certainly, owning a waterproof metal detector opens up great new detecting opportunities. A waterproof detector is ideal for use on beaches and also whilst snorkelling. You can have fun with a waterproof metal detector on river banks, freshwater beaches and in rivers. Waterproof metal detectors are not cheap to buy. However, they do open up many new possibilities for your hobby.

There are two types of waterproof detector:

There are two main types of underwater metal detectors that use different technology and it is good to spend time learning about both types to understand which type will suit your style of metal detecting best.

The first type is Pulse Induction (PI) metal detectors. These transmit quick and regular electronic pulses into the ground. These electronic pulses are not affected by wet sand or minerals. However, they are very sensitive to precious metals. PI metal detectors are great for exploring saltwater beaches and diving. For more information on how they word click here.

The second type is a Very Low Frequency (VLF) metal detector. This type of metal detector comes in a variety of strengths ranging from 3-30 kHz The main drawback with this type of metal detector is that it is affected by ground mineralisation. To offset this problem, many have a sensitivity adjustment and others have ‘ground balance control’. It is possible to adjust the sensitivity and minimise the signals caused by ground minerals by using the above features. The strength of VLF detectors can be broadly divided into three groups:

Low power 2-4 kHz which is best for coins
Medium power 5-12 kHz which detects coins, jewellery and relics
High power 12 kHz+ which is ideal for finding gold.

(more information on the above here)

* The most successful strength VLF metal detector is one that is 8-12kHz

Waterproof Metal Detector

Which waterproof metal detector for you?

Before you start your hunt for the perfect waterproof metal detector, it is best to have a good idea of exactly how you want to carry out your metal detecting. Will you want to just explore seaside and freshwater beaches? Will you want to wade in water up to your waist in search of ‘hidden treasure’? Would you like to use your waterproof metal detector whilst scuba diving or are you planning to dive to greater depths to explore shipwrecks?

It is of fundamental importance to understand what your detecting style will be so that you can check to what depth you can use your chosen waterproof metal detector. Some models have a depth rating of up to 15 feet of water (4.5m), whilst some of heavy-duty ‘professional’ models are capable of working at a depth of 250 feet (76m).

Pulse Induction (PI) models are considered the best if you are planning to dive with your metal detector. If you decide though to opt for a VLF model, check that it can definitely be used in saltwater. If you are planning to use your detector whilst diving, it is well worth investing in a short dive pole. This will make your waterproof metal detector more comfortable to use.

What other features do waterproof metal detectors have?

Waterproof metal detectors are more rugged than ordinary metal detectors as well as being waterproof. They are available in a wide range of prices, with some models specifically designed for professional detectorists and with many extra facilities. Many use Bluetooth technology as this enables objects to be pinpointed without any trailing cables. Some vibrate when the coil touches an object which is particularly good if you have a hearing problem. A number of detectors feature a ‘trash elimination’ setting which ensures you can tell the difference in what type of objects you have located.

A number of waterproof detectors can also be used for general metal detecting which is an added bonus and another point for consideration.

There are a number of leading makes of waterproof detectors such as Garrett, Fisher and Nokta. It is worth doing some research on a selection of models that appeal to you and to read some reviews online. Chatting with some detectorists on the beach can also be advantageous.

Essential accessories for metal detecting….

Headphones are an essential accessory. They cut out all external noise and this enables you to hear the deeper tones of your metal detector. All waterproof metal detectors are provided with equally waterproof headphones!

A small trowel is good for digging down to objects. A sand scoop does the work just as well and some on the market incorporate a sieve for sifting the sand in search of smaller items.

A good carry bag is well worth buying as it helps to protect your metal detector and also makes it easier to carry around.

A bag with compartments is ideal for putting your finds. It is worth keeping some pieces of rag in the bag for wrapping each individual item.

Underwater Metal Detector

Beaches – always a popular hunting ground.

It is common for detectorists to use their metal detectors early in the morning. The detectorists slowly pace up and down, headphones on and eyes focused on the sand below their detector as they wait for an alert. The chances of finding items on the beach are high. People often lose coins and jewellery that are quickly hidden by the sand. However, because the shoreline is constantly changing due to the tides, it is an enjoyable challenge.

Looking for items hidden by the sand on the beach is very rewarding. Coins are always handy or if they are old coins or foreign ones, they will be of interest. Pieces of jewellery rarely have any clues to their owner, so they can be sold for financial gain.

As well as using your metal detector on the beach, it is well worth walking/ wading along the high and low water lines and the area in between. You can search in deeper water whilst snorkelling or diving.

Time to start….

There is nothing as thrilling as hearing the wail of your metal detector. Then diving to the seabed, digging and seeing the shimmer of metal. Metal detecting is fun, requires plenty of walking – and with a waterproof metal detector, plenty of swimming too. Enjoy!


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