Each year, our Bonnier Corp. sister magazine Popular Science lists its choices for the 100 greatest new innovations in science and technology. We picked three we thought scuba divers might like.

Hydra-Light PL-500 Saltwater Light and Charger

This beachside power for gadgets is pretty ingenious: The Hydra-Light turns seawater into juice for a lantern or USB-powered devices. In the reservoir, a magnesium alloy rod slowly oxidizes in saltwater, releasing electrons in the process. A carbon-based cathode grabs and funnels those electrons to connected gadgets, providing more than 250 hours of power for illumination or charging electronics. $60

Canon 1Dx Mark II and Housing

According to Backscatter’s review, “if you’re both an underwater photographer and filmmaker, our test results confirm the Canon 1DX II is hands down the greatest camera we’ve tested to date. It’s a no compromise professional photography camera capable of shooting both 20MP stills at 14fps and 4K 60p video in incredibly low light. While it doesn’t offer the raw video and flexibility of a RED, it shoots broadcast quality 4K motion at a fraction of the size and cost and outperforms favorites such as the Sony A7 series in low noise when tasked with the extreme requirements of underwater white balance. Available from Backscatter.

Sharkbanz Wearable Shark Repellent

Scuba divers don’t really want to repel sharks; for us, this invention falls into the category of WWWWT (Why Would We Wear This?). Still, there are divers who are nervous about being close to sharks, so maybe there is a market for this item outside of surfers and swimmers. The basic concept: Muscles emit tiny electrical pulses as they contract. Receptors in a shark’s snout detect these minute signals when animals move through water, helping a shark stalk its prey. Sharkbanz — a predator-repelling wristband — contains powerful magnets that scramble a shark’s ability to read these signals — almost like getting a bright light shone in your eyes. It doesn’t hurt the animal. $65

See all of Popular Science’s Greatest Inventions of 2016. It’s pretty awesome.