Hella Marine S92 24V Dual-Tone Disc Horn Kit 113 dB

The Hella Marine S92 dual-tone disc horn kit gives you two horns in one box, a high-tone unit at 435 Hertz and a low-tone unit at 335 Hertz. Run them together off the same switch and the two frequencies stack into a deep, full note that carries across open water at 113 decibels. This is a 24-volt kit. So it's built for bigger boats, trawlers, and commercial rigs running a 24V system, not the average 12-volt center console. Check your battery bank voltage before you order.

Why two tones instead of one? A single horn tends to sound thin and easy to miss against wind and engine noise. Stacking a high and a low frequency gives you a richer sound that other boaters actually notice, which is the whole point of a signaling horn. You get that classic layered blast, the kind you hear off a working harbor, rather than a flat electric beep.

Each horn is a compact 3.58 inch round disc, so they tuck into tight spots on a hardtop, under a gunwale, or up on a flybridge without hogging real estate. The kit ships with mounting brackets for both horns, so you've got what you need to hang them out of the box. The bodies are galvanized metal and finished in black, which keeps them low-profile against dark hardware and gives them a fighting chance against corrosion.

A quick word on power. The pair pulls about 3 amps at 24 volts, since the kit is rated at 72 watts total. On a short run straight to a panel switch you can wire them directly, but on a 40-foot boat with a long cable run back to the helm, do yourself a favor and put a relay in the circuit. Feed the horns with heavy enough wire and a dedicated fuse, around 10 amps, so you don't get voltage drop that leaves them sounding weak. A relay also keeps the high current off your dash switch, which makes the switch last a lot longer.

Out in salt air, the enemy is corrosion at the mounting points. We'd hit the bracket bolts and the back of each horn with a little dielectric grease before you button it up. If you're mounting to a hardtop or a rail that vibrates, a couple of rubber isolators under the brackets will stop the discs from buzzing at speed. Do that once at install and these mostly disappear into fit-and-forget territory, which is exactly what Hella Marine builds them for.

Installation is straightforward for anyone comfortable running 24-volt wiring. Pick a spot where the horn faces outward and away from your own ears at the helm, usually forward under a hardtop lip or on the front rail. Keep the disc opening angled slightly down so it sheds water instead of collecting it. Once both horns are mounted and wired to your switch through the relay, give them a test blast at the dock and listen for a clean, blended tone. If one horn sounds off, it's almost always a loose ground, so chase your connections before you assume a bad unit.

Who's this for? Owners of larger cruisers, trawlers, and commercial vessels that already run 24 volts and want a real, attention-getting sound signal at the helm. It works as a primary horn on a boat that doesn't have one, or as a louder upgrade over a tired single-tone unit. If your boat is 12 volts, this specific kit isn't your match, and we'd rather tell you that up front than sell you the wrong horn. And remember, a horn like this covers close-quarters signaling, but it doesn't replace the sound-signal gear your vessel size may require under the navigation rules, so check what your boat needs.