Osculati Sphera 135° White Stern Light – Reliable Aft Visibility

The Osculati Sphera 11.408.14 stern navigation light is engineered to enhance your vessel’s safety by clearly delineating your boat from the rear. In dark or low-visibility conditions, this lamp projects a strong white beam over a 135° arc astern, covering from one beam (port side) across the stern to the other beam (starboard side). In practice, this means any vessel approaching from behind will spot your boat’s white stern light and be able to judge its orientation and course – a crucial factor in avoiding collisions. Designed for boats up to 12 meters in length, it meets the COLREG 72 requirements for stern lights (which call for a 2 NM visibility for vessels under 12 m), thereby keeping your boat compliant with maritime regulations.

The Sphera series is known for combining reliability with a modern aesthetic. The sturdy housing of this light is made from white, high-grade polycarbonate plastic, chosen for its ability to withstand the rigors of the marine environment – including prolonged UV exposure, saltwater spray, and physical impacts. Its construction is fully sealed to be waterproof, so internal components are protected from rain, waves, and spray that commonly batter the transom. In fact, the waterproof integrity ensures that even in heavy weather or a following sea, the light will continue to function without shorting or corroding. The Osculati Sphera stern light comes with a specific RINA certification (ELE199511CS001), indicating it has been type-tested and approved according to international navigation light standards. Inside, a 12 V, 10 W festoon bulb is pre-installed, delivering a bright and consistent aft beam. Should you wish to reduce power consumption or maintenance, you have the option to replace the halogen bulb with a compatible LED version – the fixture readily accepts an LED upgrade if desired.

Installing the Sphera stern light is straightforward. The “Sphera” design is intended for vertical mounting – typically directly onto the flat surface of your boat’s transom or on a stern rail/bracket. Choose a mounting position that offers an unobstructed view astern (for example, avoid placing it low on the transom if an outboard motor might block it; mounting it on the taffrail or an arch could be ideal for sailboats). Secure the light with two screws; stainless steel screws are recommended for longevity in a marine setting. It’s a good practice to apply a waterproof sealant around the screw holes and the wire pass-through to maintain the hull’s watertight integrity. Next, connect the light’s wiring into your boat’s 12 V electrical system. Typically, you will tie it into the navigation lighting circuit that also controls the bow lights, using the existing switch on your helm. Make sure to protect the circuit with an appropriate fuse or breaker. Once installed, the Osculati Sphera stern light provides a reliable, bright white beacon that complements your other nav lights (bow red/green and masthead) – completing the full suite of required running lights and giving you confidence during night passages.

• Typical Use Cases: Suitable for virtually all boats up to 12 m – including powerboats, sailing yachts, RIBs, and fishing vessels – that need a dedicated stern navigation light. It’s indispensable during night passages, nighttime docking, or anytime you operate in darkness or fog, as it clearly signals your boat’s presence and orientation to anyone approaching from behind. Use this light when cruising after dusk, on overnight sails, or in early morning departures to ensure you’re visible from astern.
• Recommended Vessel Size: Designed for vessels under 12 meters (approximately 39 feet), this stern light meets the visibility and arc requirements for that class. It’s an excellent choice for small-to-mid size boats, ensuring you have the mandated 2 NM aft visibility for compliance and safety. Owners of boats in this size range – from compact cruisers to midsize sailboats – will find it fits their needs perfectly.
• Installation Tips: Mount the light vertically on your boat’s transom or rear structure, as close to the centerline as possible for a balanced light spread. Position it high enough so that it’s not blocked by an outboard engine, dinghy, or any stern-mounted equipment (the goal is a clear 135° view to the horizon behind you). Seal any drilling points with marine sealant to prevent water intrusion into the hull. Wire the lamp into your navigation light switch or panel – typically this stern light will be on the same circuit as your bow lights for synchronized operation. It’s advisable to occasionally check the bulb and connections, especially before long night journeys, to ensure everything is in working order. With the light properly installed and maintained, you’ll have a bright, trustworthy stern beacon for all your nighttime adventures.