Sentinel Ocean Systems Freedom8 Shark Deterrent

The Freedom8 is a personal electronic shark deterrent from Sentinel Ocean Systems. Once it's wet it switches itself on and puts out a low-frequency electrical field between two electrodes — roughly a 6 metre bubble around you. Sharks sense it through the electroreceptors in their snouts (the ampullae of Lorenzini), find it uncomfortable and turn away. Nothing is harmed, the shark or the reef.

It's built for divers, spearfishers, snorkellers, surfers and kayakers — anyone who spends long sessions in open water and would like the odds tilted a little further in their favour. Worn on the ankle or leg in its neoprene pouch, it's close to neutral in the water, so you'll forget it's there.

What to know before you buy: a deterrent reduces risk, it doesn't remove it. It's one layer of safety alongside good buddy procedures and sensible choices about where and when you get in.

Specifications

• Protective field: approx. 6 m diameter (>1 V/m at 1 m from electrode centre)
• Run time: 4–5 hours per charge (less in cold water)
• Charge time: 3–3.5 hours
• Battery: rechargeable lithium, nominal 1,000 charge cycles, LED battery-life indicator
• Max depth: 50 m
• Operating temperature: 12–40 °C
• Weight: 1,025 g dry, 69 g in water
• Warranty: 2 years

In the box

• Freedom8 unit with rechargeable lithium battery
• Universal multi-voltage charger
• Neoprene pouch with Velcro closure
• Instruction booklet