Perko Space Saver Thru-Hull Mount Underwater Light, 12V, 30° Beam, 10 ft Cable, Mounting Ring

Overview

The Perko Smaller Space Saver Thru-Hull Mount Underwater Light is a compact thru-hull light for below-waterline boat installations where a clean underwater beam is needed without using a large hull fitting. It uses a 12V, 35W bulb with a 30° beam and draws less than 3 amps at 12 volts, making it a practical fit for conventional 12V DC lighting circuits.

This light mounts through a 1-3/4 in diameter hull opening and has a 2-7/8 in flange diameter with a 5-1/4 in overall length. It includes a safety seal design to help limit water intrusion if the glass is damaged, plus a bonding terminal for connection to the vessel bonding system.

The Smaller Space Saver format works well on transoms and hull areas where interior clearance is limited but service access is still needed. The fixture must be installed below the waterline and operated only when the outside face is fully submerged.

Key features

• Thru-hull underwater light for below-waterline installation with a 1-3/4 in mounting hole.
• 12V, 35W bulb draws less than 3 amps and projects a 30° beam.
• 10 ft of 18/2 electrical cable gives room to route wiring to a fused switch or relay.
• Safety seal design helps limit water intrusion if the glass is damaged.
• Bonding terminal allows connection to the vessel grounding or bonding system.
• Blue and green snap-in filters let the beam color change without replacing the light.
• Rear bulb access allows service from inside the vessel when conditions are safe and bilge water is below the light neck.
• Ignition protected construction supports use in appropriate marine electrical installations when wired correctly.

Variants

This light is offered in two finish configurations using the same Smaller Space Saver thru-hull format.

The finish is the option that changes between variants. Both configurations share the same thru-hull mounting style, 12V lamp format, 30° beam, 10 ft 18/2 cable, and 1-3/4 in mounting hole.

• 0175DP3PLB: Polished brass finish. This finish gives the exposed flange a warmer brass appearance for installations with traditional hardware or matching brass fittings.
• 0175DP3CHR: Chrome plated finish. This finish gives the exposed flange a bright plated appearance for installations with chrome or polished metal hardware nearby.

Installation and setup

Install the light on a flat mounting surface below the waterline so the outer flange and lens can remain fully submerged during operation. The hull opening should be sealed carefully, and the fitting should be bedded with marine sealant to maintain a watertight hull penetration.

Plan the inside-hull location before drilling. The rear of the fixture needs enough bilge-side clearance to remove the back plate and service the bulb, with at least 6 in of access behind the unit recommended for maintenance.

Electrical and system integration

Wire the unit to a fused 12V power source and size the switch, fuse, and wiring for the 35W load. When more than one underwater light is installed, the circuit should be planned so current through the switch remains within rating and ignition protection is maintained where required.

This is a hard-wired light, not a networked marine electronics device. It integrates into the boat through the electrical system, switching, grounding, and bonding layout rather than through NMEA 2000 or other data connections.

What’s included

• Underwater light in the selected finish
• Mounting ring
• 10 ft of 18/2 electrical cable
• Blue lens filter
• Green lens filter
• Two black O-rings

Maintenance and care

Disconnect power before service. Bulb changes are handled from inside the hull through the rear of the light, but the back must not be opened while the light is energized or when bilge water could enter the neck of the fixture.

Lens replacement and full fixture removal require the vessel to be out of the water. Keep the lens, filter, and O-rings seated correctly, and inspect the seal area during routine haul-outs so the installation stays watertight.