Underwater LED Light Buying Guide: Boat and Dock Lights, Colors and Brightness

By Boat Supplies Direct·Updated Oct 18, 2026·5 min read

Green underwater dock light glowing beside a dock with baitfish at dusk

Quick answer: Decide first whether you want lights on the boat (12V surface-mount or thru-hull transom lights) or at the dock (120V lights that sit on the bottom or hang from the dock). Choose green to attract baitfish and fish, or blue or white for looks. Buy more brightness than you think you need, and keep the lens clean with a foul-release coating so marine growth does not dim it within weeks.

Underwater lights turn a boat or dock into the best-looking spot on the water at night, and green lights are a proven way to pull in bait and gamefish. But a cheap light that leaks, dims after one season, or gets covered in barnacles is money thrown overboard. This guide covers boat versus dock lights, color, brightness, mounting and keeping them clean.

Step 1: Boat lights or dock lights?

	Boat underwater lights	Underwater dock lights
Power	12V or 24V DC from the boat	120V AC shore power
Mounting	Surface mount or thru-hull on the transom	Anchored on the bottom or hung from the dock
Use	Looks at anchor, attracting fish around the boat	Night fishing at the dock, waterfront lighting
Install	Wiring and transom sealing	GFCI-protected outlet, cord routed to the dock

Power draw on the boat: modern LED underwater lights draw only a few amps each, but a set of four running all evening adds up. If you anchor overnight with lights on, make sure your house battery can handle it and that the lights are on their own fused switch, not wired straight to the battery where they could drain it. Our marine battery guide covers sizing a house bank.

Step 2: Pick a color

Green: penetrates water well and attracts plankton, which brings baitfish and then gamefish. The top choice for anglers and dock fishing.
Blue: a classic, striking look. Popular for boats at anchor and waterfront homes.
White: the brightest look and shows the bottom clearly in clear water.
Color changing (RGB): lets you switch between looks with a remote or app.

Step 3: Brightness and coverage

Light fades quickly in water, especially in murky or green water. Compare lumens and beam pattern, not wattage alone. For boats, a pair of lights on the transom is the minimum for a full glow, with larger boats using four or more. For docks, higher wattage lights reach farther and draw fish from a wider area. In stained or murky water, size up.

Step 4: Mounting on a boat

Surface mount: bolts to the outside of the transom with a small wire hole. Easiest to install and replace.
Thru-hull: sits flush in a hole through the transom. Cleaner look and better protection, but a bigger install.
Mount below the waterline at the depth the maker specifies, away from the engine's water intake and transducer.
Seal every hole properly with marine sealant, and fuse the circuit at the power source.

Step 5: Installing dock lights

Plug only into a GFCI-protected outdoor outlet. Water and AC power demand it.
Bottom-anchored lights sit in the sand and point up, creating a glowing column that draws fish.
Check local rules. Some areas regulate lighting near sea turtle nesting beaches or navigation channels.
Use a timer or photocell so they come on at dusk without you.

Step 6: Keep them bright

Barnacles and slime can coat a lens in weeks in warm water. A foul-release coating made for underwater lights keeps growth from bonding, so a quick wipe restores full brightness. Clean lenses during every haul-out and inspect seals and wiring each season.

Common underwater lighting mistakes

Buying too small. Light fades fast in water. Underpowered lights look dim, especially in green or stained water.
Skipping the GFCI. Dock lights run on household AC power in water. Ground fault protection is not optional.
Mounting too close to the engine intake or transducer. Lights can interfere with sonar readings and should never block the engine's water pickup.
Ignoring growth. In warm water, an uncoated lens can lose much of its output in a few weeks.
Cheap sealing. Most failures start with water getting in at the cable entry or lens. Quality sealed fixtures and proper bedding of fasteners prevent it.

For dock lights, also think about neighbors and wildlife. A downward glow into the water is attractive, while a light shining across the canal can be a nuisance.

Our picks

All in stock at Boat Supplies Direct.

Frequently Asked Questions

What color underwater light attracts fish?

Green. It travels well through water and attracts plankton, which draws baitfish and the gamefish that feed on them.

Are underwater boat lights worth it?

For boats that anchor or raft up at night, they add a great look and can attract fish. Choose quality sealed LEDs so they last.

Do underwater dock lights need a GFCI outlet?

Yes. Any AC-powered light used in or near water should be on a GFCI-protected circuit for safety.

How do I keep barnacles off underwater lights?

Apply a foul-release coating made for lights, and wipe the lens regularly. Growth releases easily from coated lenses.

Surface mount or thru-hull underwater lights?

Surface mount lights are easier to install and replace. Thru-hull lights sit flush and look cleaner but require a larger hole and more work.

How many underwater lights does my boat need?

Two is the minimum for a good glow on most boats. Larger boats often use four or more spaced across the transom.

This guide is general information. Follow the manufacturer's installation instructions, use GFCI protection for AC lights, and check local lighting rules.