Utility 77 135° White Stern Light – Aft Lamp for Boats up to 12m

The Osculati Utility 77 11.425.04 is a stern navigation light that provides peace of mind and safety during nighttime boating, by clearly delineating the aft end of your vessel to others on the water. This light covers a 135° sector behind your boat – from one beam (side) across the stern to the other beam – allowing anyone approaching from behind to see your boat in advance and judge its course. For yachts and powerboats up to 12 meters, having a bright and reliable stern light is a must per COLREG72 (requiring a 2 NM visibility), and the Utility 77 delivers on that requirement in a compact, durable form.

The Utility 77’s construction stands out for its resilience and practicality. The sturdy white polycarbonate housing is further reinforced with a textured surface, which not only gives it a modern appearance but also helps hide scuffs and provides a better grip during installation or removal. The light is engineered to withstand harsh conditions: it is completely watertight (rated IPX6+), meaning heavy rains, strong transom spray, or constant salt exposure won’t infiltrate the interior. Additionally, the plastic is UV-stabilized, protecting it from aging and cracking under the sun. The Osculati Utility 77 stern light carries a RINA certification, confirming that its light intensity and range meet international standards for boats up to 12 m – in other words, it’s tested to shine sufficiently bright (visible from 2 NM) and within the proper arc.

The included standard bulb (12 V, 10 W) provides a bright, focused white beam that stands out clearly in the dark. Because of the light’s orientation and reflector, it illuminates only the area it’s supposed to – behind the boat – without blinding people on board. If you’d like to migrate to LED technology, the socket is standard and will accept an LED bulb of the same base, which would increase energy efficiency and potentially brightness. Mounting the light is flexible and easy. Typically, the light is installed at or near the center of the stern – on the transom – or on a stern rail if one is present, to elevate it a bit higher. Thanks to its small size, the Utility 77 can fit into limited transom spaces, among other equipment (for instance, between engine mounts or above a swim platform). It attaches with two screws; if the mounting surface is uneven or slippery (e.g., a metal rail), make sure to use a suitable clamp or bracket for stability. As always, it’s recommended to use marine sealant under the base for extra protection against water intrusion. Connect the wires to the running light system – typically the same circuit controlled by the nav light switch on your console. After installation, the Osculati Utility 77 will serve as the “taillight” of your boat: when you’re underway at night, those behind you will see a bright white point indicating your stern, cast far into the distance to protect you.

• Typical Use Cases: Suitable for all types of boats up to 12 m – sailboats, powerboats, fishing vessels, inflatable RIBs – that require a clear, dependable stern light when underway at night. It’s especially valuable when traveling in channels or being followed by larger ships: the bright stern light helps those behind gauge your distance and course. It’s also useful during night watersports (e.g., towing water-skiers at dusk) or in the event of stopping on the water at night, as it clearly signals your presence from behind. In essence, whenever your boat is out in the dark, this stern light is working to keep you safe by marking your trailing end.
• Recommended Vessel Size: Built for vessels under 12 m, the Utility 77 stern light covers their visibility (2 NM) and arc needs. For boats significantly under that size (say 5–6 m), it provides extra visibility beyond the minimum required, which is a plus for safety. For boats right up to 12 m, it ensures they’re not outshone by larger ships, fully meeting all standards. If your boat is in this category, you can trust this product to give you the necessary aft illumination mandated by law.
• Installation Tips: Mount the light as close to the center of the transom as possible, in a spot where it won’t be blocked by the engine (for outboard-powered boats, try to position the light above or to the side of the engine). If your boat has twin engines, install the light between them or on a crossbar above them. The goal is for the beam to have a clear “view” rearward. If mounting on a rail, you might need an additional clamp – either one specifically made for this light or a universal one – ensure it’s firmly attached and aims the light horizontally aft. Connect the wires securely and waterproof the connections (heat-shrink tubing is an excellent choice). Before your first night voyage, test the lamp in the dark while standing a short distance behind the boat – the light should be clearly visible and not flickering due to vibrations. With a regularly maintained Osculati Utility 77, your boat will meet all requirements for stern lighting at night and provide you with safety and confidence during after-dark cruising.