During the water hunting season, many visitors have been asking about the best type of metal detector to use for beach or shallow water hunting. To benefit everyone, I have chosen one of these questions and will provide an answer. There are several lessons to be learned from this.

The Question:

“My wife and I purchased an underwater metal detector from a well-known company recommended by a large mail-order firm. However, the model we purchased seems to perform poorly when used at the beach.”

“The main issue is that our detector starts to give false signals and make chattering noises as we approach the wet sand, and it gets even worse as we enter the surf. I was wondering if you had any suggestions or recommendations that might help us make some good finds with our detector?”

The Problem:

It seems that the detector mentioned in the email was a decent one, but not the most suitable for the specific conditions the couple was planning to search in. The detector uses a VLF circuit which is best suited for fresh-water hunting, not salt-water. As a result, it may have had some erratic operation in the area where they were searching due to the saltwater conditions.

Many saltwater beaches contain mineralized black sand to some extent, which can affect the detection capability of conventional VLF-type detectors. These detectors struggle to ignore the rapidly changing mineralization and provide accurate discrimination that is necessary to reject unwanted targets. Although there are ways to use your detector under these conditions (which I will discuss later in this column), a pulse-induction or multi-frequency VLF detector can provide better target detection depth in your area.

I have spoken with many treasure hunters who bought their metal detectors from a mail-order company to save money. Unfortunately, most of them were disappointed either because they were not recommended the best detector for their needs or because the company did not provide adequate technical support after the sale. Although the recommended detector is of high quality and reliability, it is not suitable for use in salt water.

If they had consulted with a local dealer or spoken to local treasure hunters, they would have had the chance to discover what tools were effective in their particular area. This would have enabled them to purchase a unit that likely would have helped them find more treasure than they saved by buying from a mail-order company located a thousand miles away.

The Solution:

To improve your metal detector’s performance at the beach, you can adjust the sensitivity level on a VLF-type detector. By doing so, you’ll reduce the effect of salt and black sand on the detector’s operation. To explain this better, imagine the sensitivity control on your detector as the high/low beam control for your car’s headlights. When it’s a clear night, your high beams will allow you to see much further than your low beams. However, on a foggy night, high beams will reflect towards the vehicle, resulting in almost a total loss of visibility.

Lowering your headlights to the low beam setting can help you see further in certain conditions. Similarly, reducing the sensitivity of your detector can minimize the impact of salt and black sand on the equipment. This will improve the signal from your coil and provide you with more reliable depth readings in the field. Ultimately, having more usable depth is the most important factor when metal detecting.

To Summarize:

An effective technique to enhance your accuracy in metal detecting is to hold the coil a few inches above the sand while searching. This method can be especially helpful in minimizing the impact of mineralization on your detector’s performance, much like reducing the sensitivity setting. By keeping the coil off the surface of the beach, you can ensure that your detector is not influenced by the minerals that exist in the sand. An effective technique to enhance your accuracy in metal detecting is to hold the coil a few inches above the sand while searching. This method can be especially helpful in minimizing the impact of mineralization on your detector’s performance, much like reducing the sensitivity setting. By keeping the coil off the surface of the beach, you can ensure that your detector is not influenced by the minerals that exist in the sand.

I recommended that if the users were still unhappy with the performance of their current metal detector in saltwater conditions, they should consider purchasing one of the pulse-induction or multi-frequency VLF-type detectors that are currently available in the market. These types of detectors would perform much better than their current model.