Beasts on the Beaches: Navigating Wet and Heavy Sands With the Minelab Manticore

Detecting in Southern California has posed some challenges not always seen elsewhere in the USA. Since the Navy brought me to San Diego, I’ve taken quite an interest in metal detecting. The conditions presented really can set a detectorist up to either be disappointed or reap the rewards these beaches have to offer.

Challenges of Black Sand

Some of the challenges that have been obstacles for myself and those I’ve had the pleasure of detecting with or meeting on the beaches include the presence of black sand—not just the streaks you may find in other places, but pure black magnetic sand. This can make signals stray and change VDI readings so wildly that even mid-conductors may register as an overload signal. In black sand conditions, presented after wave activity removes the top layer of sand, coins can also present themselves as iron signals.

Detecting in Black Sand

When detecting under these conditions, using ferrous limits in any beach program- with the horseshoe/ All Metal Mode function activated on the Manticore—It’s important to note that when an item is in the ferrous limit (the grey area), it will still result in an iron grunt, disabling all-metal mode will silence the signal, IE in the (grey area)

Focus of This Article

What we are going to focus on in this piece is:

• Detecting in wet sand
• Making signals sound off in black sand
• Making judgments about the target
• Optimal settings
• Changing the thought process behind detecting when these conditions exist

From what I’ve found, there are some strategies you can apply to the machine to strengthen those signals and identify items that are deep in these layers or even coins that have sunk below the black sand layers. Coins can be effectively detected even in these conditions at depths considered beyond what is typically regarded as deep for beach finds.

Minelab Manticore Custom Program, Recommended Settings

Starting Off

The first part of this discussion involves the settings I’ve found to work best. I like to start off in Beach Low Conductor as my base. Although this program is not overly complex, it is undoubtedly the best program I’ve discovered. Below are the settings, along with the reasoning behind each one:

1. Ferrous Limits:
   • Use this program with an almost wide-open setting by adjusting the top bar to 0 and the bottom bar to 0. This setting should not deviate wildly unless you have major EMI issues.
2. Recovery Speed:
   • Move this to 6 or 7. This allows for better target separation and can prevent a lot of the chatter you will experience.
3. Ground Tracking:
   • Turn off ground tracking. Multi IQ+ is remarkable in that you should not have to engage auto tracking unless it’s a last resort to silence the machine. Manually ground balancing frequently will yield better results. If you use auto tracking in extreme black sand, it may balance out so high (in the 70-85 range or more) that you will lose the sounds of coins presenting as iron.
4. Audio Themes:
   • Shift to Prospecting Audio. If you are more attuned to depth tones, this theme can also be successful.
5. Tone Type:
   • Push the edit button and adjust the tone type from rich or medium to simple. It is important to note that these options are no longer available when in prospecting mode.
6. Discrimination:
   • Adjust your discrimination to cancel tones 1-2. This will reduce chatter, although a very small percentage of gold can come in this range it would be almost impossible to detect gold that small in black sands.
7. Sensitivity:
   • Conduct a rolling noise cancel and adjust sensitivity to a point where you receive a series of softer chatter. This chatter should be ignored. A good way to understand what an actual target sounds like is to swing over your scoop and gauge the loudness. What you’re looking for in this program I nice loud responses.  I typically run the detector anywhere from 21-28 depending on the conditions.

Adjusting Ferrous Discrimination and Tweaking

Once you are in these settings and pushing the limits of what a target will sound like versus a false signal, it’s now time to adjust your ferrous limits a final time. This is akin to taming the beast, so to speak, by eliminating 1 and maybe 2 on the Top Bar you can achieve a sense of calming the detector.  Be cautious not to lower this top limit excessively, as you will then be working against yourself. The maximum top bar ferrous limit level should be not more than 2.  If you still receive feedback, you can consider pushing it to 3.

This will allow all iron and all good targets to produce a favorable tone. Fear not, as this is where the 2D screen will come into play. When you swing over a target, it will show a trace on the 2D screen. Targets that trace directly along the center line are most likely good targets, just as you would dig in any other mode.

Reading the 2D Screen

To tell the difference between good and bad targets, focus less on the VDI for the most part. Your emphasis should be on how the detector reacts to the target on the 2D screen and whether you have a trace or not.

What to Look For:

• Good Targets: Look for targets that trace from the top all the way to the bottom in a straight vertical line. You want to see a little black smudge on the top, a little black smudge on the bottom, and a larger smudge in the middle, all connected.
• Less Ideal Targets: A good vertical trace that does not connect to the bottom might not be ideal, but still worth digging.
• Targets to Avoid: Those that produce little to no sound with minimal trace and those that are angled from the left on the top moving right to the center and then to the bottom right. These are likely bottle caps and iron signals.

Make sure to change directions on your target. If it disappears or starts tracing poorly, I typically pass without taking a scoop. But this is a decision you must make on the spot, as not all targets present the same way even daily.

Swing Technique Matters

There is one more important part of this program you should focus on because it is essential to maintain a very even and level swing. The best height to keep your coil is almost in contact with the sand 1/16^th to 1/8^th of an inch above. You will get a “woomp woomp woomp” at the ends of your swing if you are arching your swing. By keeping your coil nice and level, you will be able to increase sensitivity, and after a few outings focused on your swing, you will gradually be able to up your sensitivity further.

The Silver Lining of Black Sand

When detecting heavy black sand, consider this situation a good sign. It often indicates a low beach, which helps retain many targets in place, as it counteracts the waves’ ability to move or drag targets. While black sand may require you to dig more iron, it also increases your chances of finding valuable items, such as a nice gold ring. With the right settings, it’s not uncommon to pull good targets from depths exceeding 18 inches.

Conclusion

As always, good luck and happy hunting! If you’re looking for tips and pointers on programs, feel free to reach out. If the program works for you, I would love to hear about your finds and share your experiences—good or bad. You can find or contact me through the Focus Speed Facebook group.