Fisher CZ-21 Metal Detector Review (10.5 inch Coil)

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Hunting at the beach or underwater requires some specific specs and features.

Not only do you want something that can deal with saltwater signals but also something that is submersible and can discriminate accurately.

A high-end metal detector that can do it all is the Fisher CZ-21.

It’s rated for serious underwater depth, has easy manual ground balancing, and incorporates dual-frequency detection for double the amount of target information.

If you’re not yet sure what your upgrade looks like, well, it looks like this.

At a Glance…

✔️ Best Feature: Multi-frequency

Worst Feature: Non-interchangeable searchcoils

👌 Ideal For: Underwater, Diving, Freshwater, Saltwater, Beach, Coin, Relics, Jewelry, Silver, Intermediates, Experts

  • Multi-frequency
  • Excellent features
  • Touch sensor PP
  • Lightweight
  • Made in USA

Fisher CZ-21 Metal Detector Review 10 inch coil
Image Credit – KellyCo

Our Verdict: The Fisher CZ-21 is the upgrade to the CZ-20 that many loved. With the new 21 in hand, you’ll have one heck of a detector that goes deep underwater, uses two frequencies, and has new features that will improve your chances of finding more good stuff. Coins, rings, treasure – the hunt is yours.

Who is the Fisher CZ-21 Quick Silver Best Suited to?

The CZ-21 is considered an upgrade for someone who wants something more powerful than a single VLF and can work in underwater and saltwater environments.

It is a metal detector that costs over $1000, so it’s usually put up against Minelab’s Excalibur II. Which one should you get?

The Excalibur II is also a multi-frequency machine but with 17 frequencies. It’s lightweight and excellent for land-use. However, the Fisher can go another 50 feet deeper underwater, so if you want the extra depth performance for diving or want to save a little money upfront on the initial cost, the CZ-21 is the better buy. Plus, it has a year longer warranty coverage than the Minelab.

How Does the Fisher CZ-21 Quick Silver Perform?

The Fisher CZ-21 is a performer and should not be underestimated. It’s worth the price and can be practically used on both land and underwater. But where it’s really put to max use to bring out its full potential is at the beach and diving.

It’s rated for 250 feet submersion, so exploring serious depth beneath the breaking waves is now a reality. Even if you don’t dive, the Fisher metal detector provides excellent beach and wet sand performance.

You have the ability to not only fine tune your settings, but you can run it silent without hearing the continuous threshold. This may be what gives it an upper hand than its alternatives.

Furthermore, the CZ-21 has excellent discrimination, and this is something that pulse induction detectors can’t compete with. While you may be running it without any discrimination at the beach, you still have the ability to learn the tones and pass up pull-tabs and bottle caps.

At the end of the day, the Quick Silver metal detector is easy to use, ready to get hunting immediately, and can hunt in all terrains from the fields to the ocean floor.

Features & Benefits

Fisher CZ-21 metal detector with 10 inch coil
Image Credit – KellyCo


The Fisher CZ-21 provides the powerful discrimination of VLF but the simultaneous frequency performance of a multi-frequency metal detector.

The CZ-21 Quick Silver is made in the USA by Fisher and is a high-quality metal detector for underwater, diving, saltwater, and beach hunting. With two frequencies working simultaneously, you have twice as much target analysis going on.

The VLF frequencies are 5 kHz and 15 kHz – ideal frequencies for those on the hunt for coins, relics, and some gold and jewelry.

To achieve immunity to saltwater conditions which is especially important when you’re in and around wet sand and in the surf, the VLF frequencies are run by the patented Fourier Domain signal analysis technology. It essentially cancels out signals from saltwater even when you’re running with high sensitivity. The most you should ever hear if you hear anything at all from falsing is a whisper. Ignore it.

Excellent Detector Features

controls on Fisher CZ-21 metal detector
Image Credit – KellyCo

The Fisher is feature packed even though it may not seem like it. For an unassuming Fisher metal detector, it performs excellently.

Made for diving, the CZ-21 is rated for 250-foot depths underwater. That’s about 80 meters deep. It’s not as deep diving as the 100m pulse induction Aquapulse AQ1B, but it doesn’t cost as much, and the Fisher has manual ground balance whereas the Aquapulse does not.

With multi-frequency, you have the ability to discriminate as needed, although many sit in all-metal mode and dig it all. The on-board volume control also provides a Faint-Target Audio Boost. Past volume 5, strong signals remain at a consistent volume level while weak and deep target signals continue to sound louder.

3-Tone Target-ID, three search modes (including pinpoint), and Big-Target Alert finish off the list of the extra bells and whistles the CZ-21 sports. All in all, it has the makings of being a great metal detector.

Touch Sensor PP

That big gold button thingee is the Pinpoint activation button. It’s not a button that you depress but a pad that you touch. It activates pinpoint mode with a single touch and is deactivated again by a single touch.

This may take some getting used to especially if you keep thinking that it’s a button. But we can assume that the idea is to provide touch sensor technology instead of a button to avoid accidental pinpoint activation and deactivation due to water pressure when deep diving.

While it may be something new, it works accurately. Better yet, it’s responsive even with gloves on!

One thing to note is that the PP mode uses VCO audio. You’ll know when the buried target is directly below the central axis of the coil when the audio has peaked in pitch and volume.


The CZ-21 definitely has size on its side. Completely assembled with the headset, the entire assembly weighs no more than 6.1 lbs. While this may be borderline heavy for land use, it’s still doable for anytime you want to search the dunes to the woods.

Not all submersible metal detectors are as compact as this Fisher one. Take for instance the high-grade Aquascan Aquapulse AQ1B that has excellent depth detection and a submersion rating of 100m using pulse induction. It weighs in at approximately 12 lbs with the 15” searchcoil. That’s a lot of weight to carry if you decide you’re done diving and want to check out shallow waters, coves, and anywhere else on land.


10 inch coil on Fisher CZ-21 metal detector
Image Credit – KellyCo

Non-Interchangeable Searchcoils

The downside is that you can’t switch out the concentric, co-planar searchcoils, so you must be confident in the size you want when you buy it.

You can buy the CZ-21 with the 10.5” searchcoil and the 8” searchcoil. There isn’t a huge difference in overall assembled weight as the 10.5” comes in at 6.1 lbs while the 8” comes in at 5.11 lbs.

As far as a price difference, there really isn’t one. The 10.5” is the way to go to cover more ground and gain a little more depth.

Popular Questions

What is the Shaft on the CZ-21 made from?

The CZ-21 Quick Silver shaft is lightweight at almost 3 lbs and is made from fiberglass reinforced nylon.

What comes in the Fisher CZ-21 Quick Silver Box?

The Fisher CZ-21 comes with the metal detector that has a fixed searchcoil and fixed, submersible, wired headphones. You will need to assemble the metal detector together and all the parts from the foam hand grip and armrest to the screws and wingnuts will be provided. A belt clip is also included.

What Type of Batteries does the CZ-21 Metal Detector Use?

The Fisher CZ-21 is powered by 4x 9V batteries. The battery compartment is separately sealed-off on the rear end of the control housing to protect the electronics from water damage. While you will acquire 35-55 hours of operation with alkaline batteries, you can use rechargeable Nicads but will only get 10-20 hours of operation.

What do the Circled Numbers on the Control Module Mean?

The circled numbers indicate the preset levels for that feature. Level 5 at volume control is the preset audio for Boost. Level 4 at the DISC control is the preset setting for discrimination. Level 3 at the sensitivity control is the preset setting for saltwater while level 7 is the preset setting for freshwater. Level 5 at the ground balance control is the preset setting for ground balancing. Of course, all these levels are just preset settings, but they are adjustable for fine-tuning.

What is the Warranty on the Fisher CZ-21?

The CZ-21 is warrantied for a period of 2 years by Fisher Labs. It starts from the date of purchase, proof of purchase is required, and it applies only to the original owner.

If you live outside the United States and require warranty coverage, you will also be responsible for shipping costs. 


The CZ-21 is an extremely versatile metal detector. You can be ankle deep, knee deep, waist deep, and even 250 feet deep in the water and still acquire excellent performance.

The control module can be attached to the shaft or hip mounted for a lightweight setup and comfort. It’s light enough to be used both in the water and on land. It discriminates accurately. You can run it silent. It has fast and easy touch sensor pinpointing. It boosts weak and deep signals.

What more can you ask for? A metal detector that nails it in water sources and especially in saltwater environments is a metal detector worth having. There is no hunting ground off limits to you with the Fisher CZ-21.

Further Reading:

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