I freely admit that underwater detecting is my passion. There are several reasons for this.

As a keen sea fisherman, I owned a fishing boat for many years before I started metal detecting. I was always captivated by the thought of there being treasure in the sea as well as fish. When waiting for the fish to bite we would often wonder what might be down there just waiting to be found. Part of my enjoyment in sea fishing came from planning the trips and keeping a log of all of the tides, weather, sea conditions, baits used and fish caught. I would spend hours pouring over charts and studying tidal flows, seabed contours and sea temperatures. It wasn’t just a fishing trip, it was hunting and I had to work out my tactics to catch the biggest fish possible. Underwater detecting has many similarities, especially if you want to locate big finds.

Being partially disabled I find it difficult to walk on fields, although I cope better on beaches with firm sand where my bad leg can find its own angle of support. When I first tried underwater detecting it was as though I had had a leg transplant. The pleasure of being able to walk about in the water with the buoyancy of the wet-suit taking the weight off my leg is a fantastic experience that I wholeheartedly recommend to any detectorist with a similar disability.

Shallow water detecting, the variant described here, can be carried out around much of the Mediterranean and the Adriatic, as well as in Europe’s many inland lakes, owing to the small tidal variation (or, in the case of the lakes, none at all). This means that, unlike around the British Isles or along the Atlantic coasts of France, Spain and Portugal, the water line on the beaches is more or less static.

Where you have a tidal movement similar that along the Atlantic coasts, underwater detecting is really only needed below the Spring Tides low water mark. On these types of beaches the majority of the sea area in which people swim and play will be uncovered as the tide goes out twice a day. Coins and artefacts that have been dropped can be recovered using the beach detecting methods (see Chapter 12).

BEACH BEHAVIOUR

It is a useful observation to compare the activities of people when they are in the water at Mediterranean resorts with how the public use the water at British resorts. After the size of the tides, the single biggest difference between the areas is the ambient temperature. In the UK we experience summer temperatures of typically around 20 degrees (should we be fortunate). On Mediterranean beaches, however, temperatures of 40 degrees in the shade are quite normal in high summer, while on the open beach in the direct sun a temperature of 65 degrees or more may be reached.

People on British beaches mainly use the water for a swim, to play games or ‘take a quick dip’. Abroad I have noticed that, while some go into the water for a swim, the vast majority go in to cool down and often spend up to an hour at a time just standing or bobbing up and down in shoulder-deep water. Many others sit in the shallow water with just their head and shoulders out of the water.

The effect of spending this amount of time in the water, as we all know, is for your hands and fingers to shrink and become rather wrinkled due to the beginnings of hypothermia. These are the same hands that were used to apply suntan oil back on the beach, causing rings and bracelets to slip off with remarkable ease. People sitting in the water are often seen running their hands through the sand on the seabed. Again it is very easy to lose a ring, bracelet or watch while doing this. Once a piece of jewellery has come off it disappears instantly and no amount of running your hands through the sand will help you find it. You will only make it sink further down.

The reason you find coins in the sea along the Spanish Mediterranean coast is that the men wear swimming shorts and carry money to use in the bars and other beach concessions (see Chapter 12). When they sit down in the water the pockets are horizontal and it is very easy for coins to fall out. Those who stand in deeper water bobbing up and down are just as likely to jog coins out of their pockets. Add in those who are playing games, duck diving and doing handstands in the water and it is no wonder that there is so much gold, silver and coins to be found. It is not unknown to have to come out of the water to empty my finds pouch partway through a session because it is full to capacity.

It is not just the value of the coins. It is their sheer quantity. A recent holiday produced a total haul of nearly 2,000 Euros. It was a surprise to look at them in a different way and count the actual numbers – more than 6,100 individual coins. Whichever way you look at it, that’s an awful lot of holes to dig.

Lakes

On the type of beaches created around lakes, while the sand can be moved around by the wind and weather, artefacts more or less stay where they are dropped. This is because lake beaches are largely unaffected by wave action.

The same applies to such as coins or jewellery lost in the water of the lakes. During the winter waves are created during high winds or storms, allowing items to sink lower into the silt, but there are no currents in the lakes to move articles around. This gives the underwater detectorist the opportunity to start a search by immediately adopting the double gridiron search pattern (see Chapter 4). This type of search will offer the best chance of recovering any finds in the area of the lake most used by people to swim or play.

Owing to the way people spend their time in the water, there is little point in detecting past the maximum wading depth. However you must cover from the very edge of the waterline on the beach out to the deepest you possibly can.

COASTAL BAYS

When you first arrive at a new bay on the coast, select two landmarks on the beach and a single point out at sea or on the horizon; this could be a buoy, a prominent feature or a distant mountain peak. These will form the boundary markers for your search pattern. Do not be too ambitious with the size of your area as it is hard work wading in the water swinging a detector back and forth. In a new bay the first search pattern to try is the envelope pattern (see Chapter 4). This pattern helps to give you a feel for the shape of the seabed and identify any trenches or gullies the currents have scoured out. Having completed this search, analyse whatever finds you have recovered and what you have learned of the seabed. While you take a break from the water, make a preliminary map of the bay, including any features on the seabed and the position of the finds and what type they are.

At this stage always look for any hotspots (areas of multiple finds) and for any features on the seabed. Depending on what shows up, choose a hotspot or gully and then carry out a gridiron search pattern targeting this area rather than the whole bay. From first arriving at the bay to completing this evaluation and search may take about four or five hours, which is probably enough for one session. The next stage is to bring the map up to date and then decide whether the next day you should:

If you are lucky enough to find one or more hotspots, make sure you can return to them again in the future. Hotspot locations are an invaluable resource for any detectorist. I know of certain hotspots in France and Spain that have each yielded as many as two or three hundred items over the years. In order to achieve these results you must be able to return to their exact location. Take bearings of prominent landmarks with a compass and log them on your map. Make sure you pick features that are likely to be there when you next visit, such as towers, lampposts and buildings. Buoys in the sea can get brought in during the winter months or moved by stormy weather. Even large trees can get felled. Be warned, take care not to lose a good hotspot.

The skills you initially learned by concentrating and learning the language of your detector (see Chapter 4) are vitally important when underwater detecting. Because you are unable to physically ‘see’ the seabed, it is necessary to build up a clear mental picture of what is beneath the surface. Learn to use all of your senses to understand what is happening when in the water. Even the smallest hump or depression in the seabed, for example, must be felt with your feet. Does the seabed slope from left to right or right to left? Is it going down and deeper or up and shallower? Can you feel the current on your legs and body, in which direction is it travelling and how strong is it? You may well find that, when trying to get the very most out of the machine and increase your concentration, it is better to close your eyes.

All of the information in this chapter is not much use unless you also know how to recover your finds. On the beach, as we have seen, it is not too difficult to locate the item, carefully dig the target out and recover it using a sand scoop. In shallow water the recovery system is largely the same: dig the item out from the seabed with a backhoe or similar tool, and then use the sand scoop so that the sand and water can drain out leaving the find behind.

What do you do, however, once you cannot bend down without your head going underwater? From this point, out to your maximum wading depth, is an area that holds some of the richest finds, so how do you recover the target signals?

For this you need a digging tool that will enable you to dig down into the seabed, possibly to a depth of 40cm if you are using a PI detector, then collect a target item securely and then enable you to raise it to the surface single-handed, rinsing out the sand and gravel while allowing the find to remain in the scoop. All of this should be carried out while standing in 1.4m of water or more.

There are four functions such a tool has to perform:

After trying several commercial alternatives I decided to make my own. My inspiration came from watching a ditching excavator at work on nearby farmland and performing the same four actions that the underwater digger had to carry out. The main difference between the excavator I was watching and a digger you would see working on a building site was that the ditching excavator had a mesh bucket, allowing the water to drain away. A digger-shaped bucket of mesh type construction would provide the solution; it would dig, collect and rinse, but how could I easily raise it to the surface? The answer eventually turned out to be floating rope.

As can be seen in the accompanying photographs, the bucket is a standard JCB digger shape and is made from laser-profiled stainless steel of a marine grade. It is mounted at an angle of 45 degrees on the end of a hickory handle shaft, which should continue to last for many years in and out of seawater. The attached floating rope is always available at or just below the surface of the water and enables the digger to be recovered single-handed. I have experienced no problems with the design during the five years that I have used it for detecting abroad. It is covered by registered design rights.