The Cobra Beach Magnet is one of the few dedicated beach and water metal detectors affordable enough for beginners. It makes some bold claims about its performance: watertight seals for chest-deep hunting; powerful scanning that, depending on where you look in its marketing materials, may or may not include gold detection; sturdy construction that can withstand salt and fresh water; and a five-year warranty. On the surface, there's a lot to love about it, but look deeper and the Beach Magnet comes up short.
Since it's designed for use in the water, Cobra's detector lacks many of the features you'd find on a general-purpose machine, like a display screen, target ID or a dedicated pinpoint mode. There's no interchangeability of the search coil or headphones, and while that's unsurprising on a water detector, it is still disappointing. Additionally, there is only a single audio tone to help you differentiate targets beneath ever-shifting beach sands. It does, however, sport fully variable sensitivity and discrimination knobs, which give you a degree of search field customization that most detectors can't match.
If the Beach Magnet could hold its own, this lack of features wouldn't be a concern, but the detector struggles in areas where it should be excelling. Chief among them is its construction: flimsy and cheap. Connections between components in its control box are weak, its battery wires are prone to fraying, and its headphone cord is just short enough to annoy. Most critically, while the Magnet's parts operate well in fresh water, they tend to corrode after extensive use in and around salt water – a considerable failing for a detector that's meant to be used in the ocean.
The Beach Magnet also has confusing and conflicting messages in its marketing materials. Cobra touts the detector's high, 12.5kHz operating frequency as being specifically tuned for gold detecting, yet those boasts are quickly followed by a disclaimer stating that the detector is not intended for gold prospecting – and indeed, it struggles in locating gold rings and jewelry, much less nuggets. Though it's marketed with a five-year warranty, the detector only carries a full warranty for 90 days; after that, you're responsible for covering any labor costs for repairs.
Since most all-purpose detectors are perfectly capable of searching in shallow water, the only advantage the Cobra Beach Magnet boasts is letting you wade a few more steps out into the ocean. It may be water resistant, but it can't be submerged, so don't expect to go diving with it. Given its poor build quality, its lack of features and the fact that so many alternatives can do so much more, this machine falls far short of the best metal detectors we reviewed.
Its control box can withstand accidental splashes, and its integrated headphones are water resistant.
Using it in and around salt water corrodes the detector's frame and control knobs, and its general build quality is poor.
Plan on being extremely gentle with the Cobra Beach Magnet and using it only at fresh water beaches.