Collection: Through-hull lights

Through-hull lights: underwater lighting integrated into the hull

A through-hull light is an underwater light installed through the hull, with an optical assembly flush-mounted on the exterior side and a technical assembly accessible from the interior. Unlike a surface-mounted light, it requires a true hull penetration and must be selected carefully: location, interior access, watertightness, power supply, controller, and system compatibility.

This collection includes Garmin/Lumishore EOS through-hull lights and associated kits. It targets high-power underwater lighting installations, often zone-controlled or via a dedicated interface. Selection is based on required power, number of lights, control architecture, and intended installation type on the boat.

EOS through-hull lights

The Garmin Lumishore EOS THX1604 is the most powerful model in this selection. It targets installations requiring high output, wide beam spread, and integration into an EOS system with a dedicated controller. This type of light suits boats where underwater lighting is part of the visual identity and permanent equipment.

The SUPRA THX804 EOS follows the same through-hull installation logic but in a more compact configuration. It may be better suited when seeking a balance between power, footprint, and number of light points. The choice between the two depends on boat size, distance between lights, area to illuminate, and desired visual effect.

Complete kit and control architecture

A through-hull light is not just the piece installed in the hull. The controller, wiring, power supply, and user interface must also be considered. The EOS TIX404 kit with two lights, hub, and LUX control center is designed as a complete set, useful when opting for a coherent architecture from the start rather than piecing components together.

For more advanced systems, control via hub, dedicated interface, or screen becomes important. Lights must be driven cleanly with clear zones and properly sized power supply. The lighting controls collection includes the control elements that can accompany this type of installation.

Through-hull installation: critical points

Installing a through-hull light requires serious hull work, typically with the boat out of the water. Before selecting a model, verify hull thickness, drilling zone, interior access, space for the driver or controller, cable routing, and maintenance feasibility. An installation below the waterline leaves no room for approximation.

The exterior location affects light output. Too high, the light illuminates the water poorly. Too close to an appendage, propeller, rudder, or water intake, it may be masked, exposed to turbulence, or difficult to maintain. Also consider cleaning, compatible antifouling, and future access from inside the boat.

Power, beam, and number of lights

Light output must match boat size and desired effect. A single high-power light does not always replace multiple well-distributed points. Underwater light diffusion also depends on water clarity, chosen color, installation depth, and beam angle. For a uniform result, plan the overall layout rather than an isolated product sheet.

RGB or multicolor systems allow different ambiences but require suitable control. If the goal is simply functional white lighting at the stern, the installation will not be designed the same way as for a colored ambience around the entire hull.

Wiring and electrical protection

Wiring must be sized according to voltage, power, and cable length. Drivers and controllers should be installed in accessible, if necessary ventilated, areas protected from direct moisture and clearly labeled. Each circuit must have appropriate protection and routing that minimizes chafing, water ingress points, and mechanical stress.

Document the installation: locations of lights, cables, fuses, controllers, hubs, and controls. This simplifies maintenance, especially when the boat changes owners or an intervention is needed out of season.

Complementary collections

To complete or compare the installation, also see the lights collection, the lighting collection, and the lighting controls collection. Through-hull lights are a specific family: more integrated and more demanding than surface-mounted lighting, but cleaner when installation is well designed.

Skysat advice

Before ordering, validate the installation plan with the actual hull: interior access, thickness, obstacles, wiring, and desired lighting zone. The light selection comes afterward. For this type of equipment, installation quality matters as much as light output.