Tiger Shark Field Test

by Andy Sabisch

Jack Gifford founded Tesoro Electronics nearly 20 years ago and since then his company has developed the reputation of building high-quality, dependable metal detectors at affordable prices.

Over the years, Tesoro-users worldwide have recovered coins, jewelry and artifacts spanning thousands of years, often in areas that had been heavily hunted with competing brands. Jack and his staff are continually working on developing new models to provide users with greater performance and flexibility in the field. With the popularity of beach and water hunting, they focused their efforts on producing a unit that builds on the success experienced by their Stingray II and Sand Shark models. Since I am an avid water hunter myself, I was anxious to see how well the new unit, the Tiger Shark, performed in some of the lakes and ocean beaches near my home.


When selecting a metal detector, beach and water hunters have been forced to make a choice based on where they planned to hunt most often; i.e., fresh or salt water. While VLF detectors offered discrimination, they were usually adversely affected by the conductivity of salt water resulting in erratic operation. On the other hand, pulse detectors could handle these conditions; however, they lacked the discrimination found on VLF units and as a result, users were forced to dig almost every target they came across-good and bad! The only solution was to purchase two different detectors if you hunted both fresh and salt water sites or look into one of the $1,000 plus units operating on multiple frequencies. After two years of design and testing, the microprocessor-controlled Tiger Shark was born. In the NORMAL mode, the Tiger Shark utilizes the fieldproven ground balance circuitry found on other popular Tesoro models such as the Eldorado and Bandido. What sets the Tiger Shark apart from other VLF detectors is the SALT mode which activates a completely separate set of internal settings and circuitry which allows the adverse effects of salt water to be compensated for with no loss of performance. Tested in a number of different areas over the two-year period, the two modes-NORMAL and SALT-make the Tiger Shark a truly versatile detector unaffected by mineralized ground or salt water.

The Tiger Shark is controlled through four knobs on the control housing face and three small potentiometers inside the housing. The external knobs are TUNE SPEED (All Metal Slow/Fast/Motion Discrimination); MODE (Off/Normal/Salt); DISC LEVEL and GROUND ADJUST. Internal adjustments include Volume, Reprinted with thanks from Lost Treasure December 2000 Threshold and Sensitivity.

The Tiger Shark uses the same control housing that has been used on all of the other water detectors that have been built by Tesoro. Rock-solid, this case has developed the reputation of being leak proof even after years of service and is rated waterproof to 200 feet. The shaft assembly allows for the detector to be used in several different configurations including pole-mounted, hip-mounted or as a short-handle dive unit. No additional parts or kits are required for these conversions.

The Tiger Shark is powered by 8 AA batteries which, according to the manual, provide between 10 and 20 hours of life. I tend to think you will get more than this as I used the unit extensively during the field test and never had to replace the batteries. Rechargeable batteries can be used in the Tiger Shark with no adverse results. The battery pack has also been redesigned and is now a drop-in system that eliminates the potential of breaking the battery leads.

Field Test

My initial testing was conducted at a few local land sties such as schools and private yards to get the hang of adjusting the Tiger Shark and seeing how it responded to various targets. Like other Tesoro models I have used in the past, the Tiger Shark did an above-average job in handling the mineralized ground found in central Pennsylvania and located targets including a few wheat cents, three silver dimes and other items at depths up to 9 inches deep.

The first water site I visited was a small public lake in a nearby town. Unfortunately, the summer of 2000 in the Northeast has been one of rain and cool temperatures, which kept the crowds small to non-existent on most beaches throughout the season. Hoping to find at least a few "keepers"- whether from this season or previous ones, I set the sensitivity near maximum, ground balanced the unit and walked into the shallow roped-off swimming area. As expected, signals were few and far between. One thing that I noticed immediately was the lack of any chatter or false signals as I searched. This beach was in the center of the coal mining area of Pennsylvania and when I had hunted here in the past I had been plagued with "noise" from the coal cinders that were buried in with the sand. The new circuitry was doing an excellent job ignoring the "hot rocks." The first signal was quite loud and turned out to be a new Maryland quarter just under the surface. Continuing out towards the rope, I received a faint but repeatable signal. Digging down to the clay layer under the sand, I found a small 10KT gold hoop earring-not worth much but I'll take any gold target! The impressive thing was that the Tiger Shark had detected a target this small almost 7 inches down in sand that contained hot rocks. Over the next three weeks I hunted four more freshwater beaches and despite the cool weather and competition from local hunters, I recovered nearly $25 in coins, several keys, a nice dive watch (still running) and 11 pieces of gold including a rope chain that most detectors would have a hard time seeing even when placed on the coil itself.

Since moving up to Pennsylvania from Georgia, I was closer to ocean beaches than I had been in the past which was convenient for testing detectors in this environment. I called an old friend of mine-Brian Wilkin-who lived on the New Jersey shore and arranged to meet him on the beach near Toms River, N.J. He is an avid saltwater beach hunter and was anxious to see how well the Tiger Shark performed in his area. We started out in the wet sand in front of the boardwalk as Brian had done well here over the past few weeks. I switched to the SALT mode and ground balanced the unit. Sweeping the coil across the wet sand, a few "popsand-chirps" were produced. The sensitivity was still set fairly high from the freshwater sites I had been searching which was causing the background noise. Turning my back to the wind, I opened the control housing and lowered the Sensitivity slightly. Closing the case and re-ground balancing the detector, I found it to be silent as I swept across the wet sand. Even as I approached the area where waves were washing up, there was no falsing typically experienced when hunting saltwater areas with most VLF-type detectors. Brian and I planned to crosscheck each other's signals to see how the Tiger Shark compared to his pulse detector. He hit the first few signals; however, the Tiger Shark did not produce any response when I checked them. In each case the targets were ferrous trash-sparklers from the 4th of July, wire ties, small pieces of a rusted can, etc. The first signal I received was clear but faint. Brian checked it and also received a faint signal. From just over 8 inches we pulled out a well-corroded quarter slightly on edge. Over the next hour we found several coins, a key, two Matchbox cars and a few other non-ferrous items. Brian had also recovered more than two dozen pieces of rusted metal which is the downside of using a pulse detector. As we started working our way back to the boardwalk, I received a signal and called Brian over. He was not able to get a signal despite hearing the response from the Tiger Shark.

Curious as to what the target was, we carefully scraped the wet sand away. Four inches down we found a small (0.5" x 0.25") thin gold cross. It wasn't until Brian's coil almost touched the cross did he get any signal at all. On the other hand, the Tiger Shark could hit it almost an inch or two deeper than it had been found. We hunted this beach and two others the rest of the day and while we found only one more piece of gold, a small nugget ring, we did find several dollars in coins and other interesting "trinkets." Brian was impressed with the Tiger Shark's performance and was considering switching from his ol' dependable pulse unit for his daily searches on the New Jersey coastal beaches.


The Tiger Shark's unique hybrid circuitry is extremely effective in allowing it to be used in both salt water and fresh water environments as well as all types of land sites. Treasure hunters can now have a single detector that works well in all areas rather than being forced to sacrifice performance or buy two different detectors. Tesoro detectors have developed the reputation of being extremely sensitive to even the smallest of gold objects and the Tiger Shark continues to fulfill that reputation. Considering most beach and water hunters are searching for gold jewelry in addition to coins and artifacts, the Tiger Shark won't be a disappointment.

The only drawback with the unit is the need to open the case to adjust the sensitivity (typically the volume and threshold would not require readjustment once you set them). On land, this is not a problem; however, one should be careful to protect the internal electronics from blowing sand and spray when making an adjustment on a saltwater beach.

The Tiger Shark comes with the standard lifetime Tesoro Electronics warranty and sells for $749.

Tesoro offers an optional 7-inch and 10.5 inch searchcoil, which further enhances the Tiger Shark's versatility.

If you are looking for a quality detector that is equally at home on a beach or underwater as well as the local park or even a long-forgotten battlefield, you should take a close look at the new Tiger Shark.

* - Reprinted with permission from Tesoro, "Metal Detector Information" - 22nd Edition