Freedom8 Shark Deterrent Review: A Practical Tool for Divers and Spearfishermen

There is little debate among divers and spearfishermen that shark encounters in U.S. and Caribbean waters have become more common over the past decade. Whether this is due to recovered shark populations or changing environmental conditions more encounters naturally lead to more interactions.

Dealing With Curious or Aggressive Sharks

Experienced divers use a variety of techniques when encountering sharks.

One common approach is using confident body language. Maintaining eye contact, extending your arms to appear larger, making noise by yelling through your regulator/snorkel, or tapping on your speargun can discourage a curious shark from becoming too comfortable around you. Although it may seem counterintuitive, many divers have also reported success by confidently swimming toward a shark that is making repeated investigative passes.

Unfortunately, some spearfishermen have encountered situations where a shark becomes dangerously aggressive. In extreme cases involving an immediate threat to life, some divers have resorted to lethal means of self-defense, including the use of a spear or a powerhead (also known as a Personal Protection Device, or PPD).

Powerheads require proper training and should only be considered as a last resort in genuine life-threatening situations. Laws protecting shark species vary by jurisdiction, and many species remain protected from harvest. However, self-defense laws may provide legal protection when someone reasonably believes they are facing an imminent threat of serious bodily harm or death. 

Non-Lethal Shark Deterrents

Many divers prefer non-lethal deterrents whenever possible.

One well-known option is Sharkbanz, which uses powerful magnets worn as a wrist or ankle band. The concept is that the magnetic field interferes with the shark's highly sensitive electroreceptors, known as the Ampullae of Lorenzini. These sensory organs, located primarily around the head and mouth, allow sharks to detect extremely weak electrical signals produced by other marine life.

Some scientific studies and real-world testing suggest magnetic deterrents can reduce the curiosity of certain sharks. However, questions remain about their effectiveness against highly motivated or aggressive animals.

Introducing the Freedom8 Shark Deterrent

The Freedom8 from Sentinel Ocean Systems builds upon more than 20 years of research and development in electrical shark deterrent technology.

Many divers may remember the Freedom7 Shark Shield, which earned a strong reputation before production ceased several years ago. The Freedom8 is an updated version with several improvements.

Unlike magnetic devices, the Freedom8 produces an electrical field designed to discourage sharks from approaching. The technology has been evaluated in multiple independent scientific studies and peer-reviewed research, with findings indicating that electrical deterrents can alter shark behavior and reduce close-range encounters.

Does It Harm Sharks?

Current research indicates the electrical field causes temporary discomfort but does not produce lasting harm. The device is designed to encourage sharks to turn away rather than injure them.

Not every species responds equally. For example, nurse sharks appear to be far less affected than species such as bull sharks.

Does It Attract Sharks?

There is currently no credible scientific evidence demonstrating that electrical shark deterrents attract sharks.

Does It Actually Work?

Based on my personal experience and the experience of hundreds of others, yes.

Military organizations, law enforcement agencies, government departments, commercial divers, and underwater workers have used electrical shark deterrents for years as an additional layer of protection.

I've been testing Freedom8 prototypes while diving in waters where bull sharks and sandbar sharks were present on nearly every dive. The difference between having the device turned on and turned off was immediately noticeable.

With the unit switched off, sharks frequently approached within range to touch them with my speargun tip. Once activated, they maintained a distance of roughly 10 to 15 feet. In most cases, you could clearly observe the moment a shark encountered the electrical field—it would abruptly turn its head and change direction. Most of the time, they didn't come back.

While no deterrent can guarantee complete protection, my real-world experience has given me considerable confidence in the Freedom8's effectiveness.

Will You Feel the Electrical Field?

You won't be electrocuted.

Most users compare the sensation to a TENS unit used in physical therapy. If the antenna comes very close to your body, you may experience a brief muscle contraction or mild tingling sensation.

During testing, I occasionally felt my bicep or calf contract when the antenna whip came too close. It wasn't painful, although individual sensitivity will vary.

To minimize the chance of contact, many divers drill a small hole near the end of a fin or better yet in the siderail, and secure a zip tie that holds the antenna slightly farther away from the body.

Many freedivers report good results attaching a single Freedom8 to a float or anchor while spearfishing.

Does It Affect Fish?

 No

 Recreational and commercial spearfishermen have used electrical deterrents for years with no reduction in fish harvested. Likewise, there is no evidence that these devices affect fish or other marine life. Their intended target is the electroreception system found in many shark species. Fish do not possess these receptors.

Peace of Mind

One of the greatest benefits to a spearo may simply be peace of mind.

I've never considered myself afraid of sharks, but I have tremendous respect for what they are capable of. 
Using the Freedom8 allowed me to focus more on diving and hunting fish instead of constantly watching over my shoulder during repeated shark encounters.

No shark deterrent should be viewed as an absolute guarantee of safety, and sound diving practices should always remain your first line of defense. However, based on my experience, the Freedom8 is a valuable addition to any diver's safety equipment.

 

This blog was written by Rich Taylor. Rich is the owner of Spear Gods spearfishing store. He has been diving and spearfishing (sometimes commercially) for 47 years and has logged thousands of hours in the water around bloody and dying fish.

Spear Gods will be among the first retailers to offer the SOS Freedom8 shark deterrent when it becomes available in the United States so sign up now to get on the list!