Saltwater Beach Metal Detecting 101, What You Need To Know
Mar 6, 2016 19:20:58 GMT
pinenut likes this
Post by Terry Soloman on Mar 6, 2016 19:20:58 GMT
Beach and Water Detecting 101: Getting Started
By Terry Soloman
Metal detecting for coins and jewelry on America's fresh- and saltwater- beaches, has never been more popular or profitable. Folks have been going to the beach, and losing their belongings in the sand and surf, since the beginning of time. Today's metal detector manufacturers offer units specifically engineered for the surf and sand treasure hunter, and there's no shortage of beach equipment or accessories to choose from when you decide to dive in! Let’s start by looking at the machines we use to find treasure on America's beaches.
Very Low Frequency and Pulse Induction metal detectors.
The first thing to determine is what type of water, or beach you will be hunting. Are you detecting in the saltwater and on wet ocean sand, or will you be hunting dry sand and freshwater lakes and river beaches? This is important because there are different metal detectors designed for fresh- or, salt- water use. For instance, a "VLF" or very low frequency type metal detector works extremely well on dry sand and in fresh water. It does not work as well in saltwater, or on wet ocean-water beaches. In highly conductive saltwater conditions pulse induction or "PI," and multi-frequency VLF "BBS" metal detectors excel.
The VLF metal detector sends 4,000 - 80,000 radio (sine) waves per-second into the ground. When the radio waves hit something conductive - like an iron nail, gold ring, coin or aluminum pull-tab, a magnetic field sets up around the object and a particular signal frequency is transmitted back to the detector's receiving coil. VLF metal detectors have the ability to "discriminate," or tell what type of metal they are seeing by "reading" the return signal frequency.
An iron nail for example, has a different frequency than a silver coin. The processor in the metal detector knows the difference between the two, and can be set to remain silent when seeing the nail. However, the radio waves bounce off everything that is conductive in the sand or water. This is why VLF detectors must be "ground balanced" to work effectively in highly mineralized soil, or on highly conductive saltwater beaches. You must tune or adjust the machine to see through the "fog," or white-noise created by the salt and iron in the sand or water you are detecting. Unfortunately, this usually leads to a loss of depth and stability with most VLF detectors.
Minelab has a fully submersible VLF beach machine that can discriminate out iron in wet sand and saltwater. The “Excalibur” uses Broad Band Spectrum, or “BBS” technology, and retails for about $1,600.00. According to Minelab, their BBS operating system, “simultaneously transmits, receives and analyses a broad band of multiple frequencies to deliver substantial detection depth, high sensitivity and accurate discrimination for a wide range of target types.” The key takeaway here is “multiple frequencies.” Unfortunately, radio waves regardless of their frequency still have to be filtered and balanced in heavily conductive wet-ocean sand and highly mineralized saltwater. That limits the systems depth capabilities.
The magnetic iron sands (“Black Sands”), salt, and high concentrations of other minerals in the water and sand conspire to bounce the radio waves away from the target. Conductivity and mineralization act like a shield around the target and create white noise that must be filtered electronically.
Think of it as turning on your bright headlights in a heavy fog at night. All that powerful light is diffused and causes a complete white out – you can’t see anything three-feet past the hood of your car! However when you turn on your yellow fog lights, you can see a little further – not as far as you could in clear daylight, but further. That is why all radio wave machines must be “ground balanced” or tuned, to maximize their depth potential, and why BBS filters and multi-frequencies are so effective – yet still limited.
Unlike BBS and VLF metal detectors which constantly send and receive thousands of low frequency radio waves per second, a Pulse Induction (PI) metal detector fires high-voltage pulses into the sand several hundred times per second. If no metal is present the electric pulse decays at a uniform rate with no anomalies. When metal is present a small “eddy” current flows through it causing the voltage decay time to increase, which creates a measurable anomaly. Unlike VLF radio waves, electronic pulses are impervious to the effects of conductivity and mineralization, and are unaffected by salt or black sands.
Using the same heavy fog at night metaphor that I referred to earlier, pulse induction is like headlights that cut completely through the fog as if it were not there at all. The trade-off for that added depth and clarity is the inability to discriminate, or block out iron targets that you generally don’t want to waste time and energy digging. While a pulse induction machine detects all metals without discrimination, the minute differences in the signal tone and quality can give a skilled and experienced operator a clue as to what the target may, or may not be.
Beach and Water Hunting Equipment
Sand Scoop - Whether hunting fresh- or salt- water beaches, you need the right equipment to recover your targets. A good beach or sand scoop is a must. Choose your scoop based on the types of beaches you will be hunting, and the area of the beach. Generally, a long-handled large capacity sand scoop is desirable in the water. Aircraft-grade aluminum and stainless steel scoops come in a variety of shapes, lengths, weights, and prices. In the dry sand, a short-handled scoop is usually faster and easier to use. Do not buy a cheap scoop. This piece of equipment is essential - and just as important to your success as the metal detector you choose.
Finds Pouch - You will need a pouch to put your finds in. An inexpensive cloth nail pouch works great on the beach, but you will need something a bit more substantial for your wet sand and water finds. Large, open mesh, multi-pocket belt pouches with Velcro closures are ideal for the water. They allow the sand and water to rinse out, and secure your finds so they are not lost in the surf - again!
Waders - Waders are the least expensive way to get into the surf at low tide. In most ocean beach situations, waders will only be serviceable to depths just above the knee due to wave action. Important things to look for in quality waders include weight; fabric thickness; flip out storage pockets; high-density neoprene booties (rather than heavy rubber boots); and a good wading belt should be included. Lightweight slip-on beach shoes can be worn over the neoprene booties.
Wetsuits - Fit is the most important factor when purchasing a wetsuit. You must try on the wetsuit, as every wetsuit manufacturer's size chart is different. Thickness is also important. The thicker the suit, the warmer. 'Smoothie' neoprene stretches better and is warmer in windy conditions. Seams are also important. The types of seams used in a wetsuit differ greatly.
An "Overlock" seam is found on inexpensive suits. This type of stitch lasts forever but it is not watertight, and can cause skin irritation or a rash as it protrudes against the skin. A "Flatlock" seam is a flat stitch that does not push into your skin like the overlock. It is not watertight, but does not cause as much of a rash or chaffing problem.
The "Blindstitch," is a flat stitch that does not penetrate all the way through the neoprene, so there are no stitch holes. It is watertight which makes a tremendous difference. Blindstich seams are found only on more expensive wetsuits.
Last but not least, wetsuit zippers - or closures, are extremely important. "Back-zip" suits are the most common type. Look for a sturdy metal zipper (rather than plastic), and thick flaps behind the zipper to prevent water flushes. You would look for the same qualities in a "Shoulder-zip" suit.
Footwear - There are dozens of choices when it comes to beach and water shoes, and many bargains to be found. Look for a shoe that meets your exact needs. It should be metal-free, and as light as possible without sacrificing your overall comfort. Beach hunters can spend four- to six- hours gridding the sand at their local beach. Comfort and breathability are extremely important.
Hat - Anyone who spends a lot of time on the beach knows the importance of a quality, long billed cap. There are several things to look for in a good beach detecting cap. Be sure the cap feels comfortable with your headphones and sunglasses on. A cap should be breathable, and offer a sun flap to protect the back of your neck.
Sunglasses - Eye protection should be a top priority while spending long hours in the sun. Extended exposure to reflected light and glare from sand and water can cause real discomfort, and even damage to your eyes.
Beach Detecting Strategies; When and Where to find treasure on the beach
The beach is divided into two-sections - The "Dry Sand" or blanket area, and the "Wet Sand" or swimming area. When detecting the dry sand areas, successful beach hunters "grid" individual sections of the beach. Start by choosing an area 50-feet long, by 50-feet wide. First detect from the North to South. When you have detected the entire grid, turn 90-degrees and detect it again East to West.
Moving slowly and methodically, you will be able to pass your coil over every inch of the 50' x 50' area. Coins, watches, rings, bracelets, Ipods, cell phones, car keys - you'll find it all! The phrase to remember is "low and slow." Keeping your coil as low and flat to the sand as you can, while moving slowly enough to assure your sweeps overlap each other is the real key to success.
For tips on hunting the surf and wet sand I consulted with Rusty Henry. Rusty is a retired Navy "frogman," and an original Seal Team 2 member. He is a living metal detecting legend, and has been the Service Manager at Tesoro Electronics for 20-years. Rusty says rings and jewelry are lost in the water during both High, and Low tides. You can get to these treasures much more quickly during Low tide however. "At Low tide, get into knee- to thigh- deep water to get to the jewelry that was lost at High tide by people swimming, frolicking, throwing Frisbee's, footballs and such," says Rusty.
"Look for streaks of Black sand on the beach at the waterline. These are always an indicator of where other heavy things like coins and jewelry will be deposited. Many beaches will only have Black sand streaks after a storm, or unusually heavy wave action. Storms uncover things that have been out of reach for many years as the sand gets ripped away. You have to act fast however during low tides, as a couple tide changes can start covering it all up again." Rusty says after a violent storm, look for hard clay patches that are showing and, "detect the small depressions that look like miniature potholes."
Before packing the vehicle with your beach gear and metal detector, be sure to check your local city and state rules and regulations. Many states and cities are now requiring you to possess a valid "Metal Detecting Permit," and have strict guidelines for detectorists. Along the "Treasure Coast" in Florida, you may detect the dry sand and shore only to the waterline because the state leases the water rights to treasure hunters (similar to gold claims). These waters are vigorously patrolled by the state. In New York, you must have a permit to detect the state-owned beaches of Long Island. The annual permit is good from Jan. 1 - Dec. 31, and costs US$40.00. The state parks like Jones Beach, and Robert Moses, are heavily patrolled. A ticket for detecting without a permit within a NYS park is US$165.00. Do your research and have the permits and permissions required to be on the beach you will be hunting.
Whether on the dry sand or in the ocean surf, metal detecting the beach is one of the most rewarding experiences a treasure hunter can have. From pocket change and Ipods, to old coins, diamond rings and gold chains, America's beaches are living treasure troves. A healthy and heavenly place for the metal detectorist, and naturally replenished and re-seeded every spring and summer. So what are you waiting for? Let's hit the beach!
By Terry Soloman
Metal detecting for coins and jewelry on America's fresh- and saltwater- beaches, has never been more popular or profitable. Folks have been going to the beach, and losing their belongings in the sand and surf, since the beginning of time. Today's metal detector manufacturers offer units specifically engineered for the surf and sand treasure hunter, and there's no shortage of beach equipment or accessories to choose from when you decide to dive in! Let’s start by looking at the machines we use to find treasure on America's beaches.
Very Low Frequency and Pulse Induction metal detectors.
The first thing to determine is what type of water, or beach you will be hunting. Are you detecting in the saltwater and on wet ocean sand, or will you be hunting dry sand and freshwater lakes and river beaches? This is important because there are different metal detectors designed for fresh- or, salt- water use. For instance, a "VLF" or very low frequency type metal detector works extremely well on dry sand and in fresh water. It does not work as well in saltwater, or on wet ocean-water beaches. In highly conductive saltwater conditions pulse induction or "PI," and multi-frequency VLF "BBS" metal detectors excel.
The VLF metal detector sends 4,000 - 80,000 radio (sine) waves per-second into the ground. When the radio waves hit something conductive - like an iron nail, gold ring, coin or aluminum pull-tab, a magnetic field sets up around the object and a particular signal frequency is transmitted back to the detector's receiving coil. VLF metal detectors have the ability to "discriminate," or tell what type of metal they are seeing by "reading" the return signal frequency.
An iron nail for example, has a different frequency than a silver coin. The processor in the metal detector knows the difference between the two, and can be set to remain silent when seeing the nail. However, the radio waves bounce off everything that is conductive in the sand or water. This is why VLF detectors must be "ground balanced" to work effectively in highly mineralized soil, or on highly conductive saltwater beaches. You must tune or adjust the machine to see through the "fog," or white-noise created by the salt and iron in the sand or water you are detecting. Unfortunately, this usually leads to a loss of depth and stability with most VLF detectors.
Minelab has a fully submersible VLF beach machine that can discriminate out iron in wet sand and saltwater. The “Excalibur” uses Broad Band Spectrum, or “BBS” technology, and retails for about $1,600.00. According to Minelab, their BBS operating system, “simultaneously transmits, receives and analyses a broad band of multiple frequencies to deliver substantial detection depth, high sensitivity and accurate discrimination for a wide range of target types.” The key takeaway here is “multiple frequencies.” Unfortunately, radio waves regardless of their frequency still have to be filtered and balanced in heavily conductive wet-ocean sand and highly mineralized saltwater. That limits the systems depth capabilities.
The magnetic iron sands (“Black Sands”), salt, and high concentrations of other minerals in the water and sand conspire to bounce the radio waves away from the target. Conductivity and mineralization act like a shield around the target and create white noise that must be filtered electronically.
Think of it as turning on your bright headlights in a heavy fog at night. All that powerful light is diffused and causes a complete white out – you can’t see anything three-feet past the hood of your car! However when you turn on your yellow fog lights, you can see a little further – not as far as you could in clear daylight, but further. That is why all radio wave machines must be “ground balanced” or tuned, to maximize their depth potential, and why BBS filters and multi-frequencies are so effective – yet still limited.
Unlike BBS and VLF metal detectors which constantly send and receive thousands of low frequency radio waves per second, a Pulse Induction (PI) metal detector fires high-voltage pulses into the sand several hundred times per second. If no metal is present the electric pulse decays at a uniform rate with no anomalies. When metal is present a small “eddy” current flows through it causing the voltage decay time to increase, which creates a measurable anomaly. Unlike VLF radio waves, electronic pulses are impervious to the effects of conductivity and mineralization, and are unaffected by salt or black sands.
Using the same heavy fog at night metaphor that I referred to earlier, pulse induction is like headlights that cut completely through the fog as if it were not there at all. The trade-off for that added depth and clarity is the inability to discriminate, or block out iron targets that you generally don’t want to waste time and energy digging. While a pulse induction machine detects all metals without discrimination, the minute differences in the signal tone and quality can give a skilled and experienced operator a clue as to what the target may, or may not be.
Beach and Water Hunting Equipment
Sand Scoop - Whether hunting fresh- or salt- water beaches, you need the right equipment to recover your targets. A good beach or sand scoop is a must. Choose your scoop based on the types of beaches you will be hunting, and the area of the beach. Generally, a long-handled large capacity sand scoop is desirable in the water. Aircraft-grade aluminum and stainless steel scoops come in a variety of shapes, lengths, weights, and prices. In the dry sand, a short-handled scoop is usually faster and easier to use. Do not buy a cheap scoop. This piece of equipment is essential - and just as important to your success as the metal detector you choose.
Finds Pouch - You will need a pouch to put your finds in. An inexpensive cloth nail pouch works great on the beach, but you will need something a bit more substantial for your wet sand and water finds. Large, open mesh, multi-pocket belt pouches with Velcro closures are ideal for the water. They allow the sand and water to rinse out, and secure your finds so they are not lost in the surf - again!
Waders - Waders are the least expensive way to get into the surf at low tide. In most ocean beach situations, waders will only be serviceable to depths just above the knee due to wave action. Important things to look for in quality waders include weight; fabric thickness; flip out storage pockets; high-density neoprene booties (rather than heavy rubber boots); and a good wading belt should be included. Lightweight slip-on beach shoes can be worn over the neoprene booties.
Wetsuits - Fit is the most important factor when purchasing a wetsuit. You must try on the wetsuit, as every wetsuit manufacturer's size chart is different. Thickness is also important. The thicker the suit, the warmer. 'Smoothie' neoprene stretches better and is warmer in windy conditions. Seams are also important. The types of seams used in a wetsuit differ greatly.
An "Overlock" seam is found on inexpensive suits. This type of stitch lasts forever but it is not watertight, and can cause skin irritation or a rash as it protrudes against the skin. A "Flatlock" seam is a flat stitch that does not push into your skin like the overlock. It is not watertight, but does not cause as much of a rash or chaffing problem.
The "Blindstitch," is a flat stitch that does not penetrate all the way through the neoprene, so there are no stitch holes. It is watertight which makes a tremendous difference. Blindstich seams are found only on more expensive wetsuits.
Last but not least, wetsuit zippers - or closures, are extremely important. "Back-zip" suits are the most common type. Look for a sturdy metal zipper (rather than plastic), and thick flaps behind the zipper to prevent water flushes. You would look for the same qualities in a "Shoulder-zip" suit.
Footwear - There are dozens of choices when it comes to beach and water shoes, and many bargains to be found. Look for a shoe that meets your exact needs. It should be metal-free, and as light as possible without sacrificing your overall comfort. Beach hunters can spend four- to six- hours gridding the sand at their local beach. Comfort and breathability are extremely important.
Hat - Anyone who spends a lot of time on the beach knows the importance of a quality, long billed cap. There are several things to look for in a good beach detecting cap. Be sure the cap feels comfortable with your headphones and sunglasses on. A cap should be breathable, and offer a sun flap to protect the back of your neck.
Sunglasses - Eye protection should be a top priority while spending long hours in the sun. Extended exposure to reflected light and glare from sand and water can cause real discomfort, and even damage to your eyes.
Beach Detecting Strategies; When and Where to find treasure on the beach
The beach is divided into two-sections - The "Dry Sand" or blanket area, and the "Wet Sand" or swimming area. When detecting the dry sand areas, successful beach hunters "grid" individual sections of the beach. Start by choosing an area 50-feet long, by 50-feet wide. First detect from the North to South. When you have detected the entire grid, turn 90-degrees and detect it again East to West.
Moving slowly and methodically, you will be able to pass your coil over every inch of the 50' x 50' area. Coins, watches, rings, bracelets, Ipods, cell phones, car keys - you'll find it all! The phrase to remember is "low and slow." Keeping your coil as low and flat to the sand as you can, while moving slowly enough to assure your sweeps overlap each other is the real key to success.
For tips on hunting the surf and wet sand I consulted with Rusty Henry. Rusty is a retired Navy "frogman," and an original Seal Team 2 member. He is a living metal detecting legend, and has been the Service Manager at Tesoro Electronics for 20-years. Rusty says rings and jewelry are lost in the water during both High, and Low tides. You can get to these treasures much more quickly during Low tide however. "At Low tide, get into knee- to thigh- deep water to get to the jewelry that was lost at High tide by people swimming, frolicking, throwing Frisbee's, footballs and such," says Rusty.
"Look for streaks of Black sand on the beach at the waterline. These are always an indicator of where other heavy things like coins and jewelry will be deposited. Many beaches will only have Black sand streaks after a storm, or unusually heavy wave action. Storms uncover things that have been out of reach for many years as the sand gets ripped away. You have to act fast however during low tides, as a couple tide changes can start covering it all up again." Rusty says after a violent storm, look for hard clay patches that are showing and, "detect the small depressions that look like miniature potholes."
Before packing the vehicle with your beach gear and metal detector, be sure to check your local city and state rules and regulations. Many states and cities are now requiring you to possess a valid "Metal Detecting Permit," and have strict guidelines for detectorists. Along the "Treasure Coast" in Florida, you may detect the dry sand and shore only to the waterline because the state leases the water rights to treasure hunters (similar to gold claims). These waters are vigorously patrolled by the state. In New York, you must have a permit to detect the state-owned beaches of Long Island. The annual permit is good from Jan. 1 - Dec. 31, and costs US$40.00. The state parks like Jones Beach, and Robert Moses, are heavily patrolled. A ticket for detecting without a permit within a NYS park is US$165.00. Do your research and have the permits and permissions required to be on the beach you will be hunting.
Whether on the dry sand or in the ocean surf, metal detecting the beach is one of the most rewarding experiences a treasure hunter can have. From pocket change and Ipods, to old coins, diamond rings and gold chains, America's beaches are living treasure troves. A healthy and heavenly place for the metal detectorist, and naturally replenished and re-seeded every spring and summer. So what are you waiting for? Let's hit the beach!