Fishing Lights: Green vs Blue, and Submersible vs Above-Water
How a fishing light actually attracts fish, why green and blue both work in different water, and the difference between a submersible, a dock light and a flood.
By Augustus Muse · Published November 4, 2026
Night fishing under a light is one of the few things in fishing that works for a reason you can see happening. The light draws plankton, the plankton draws bait, and the bait draws what you came for, in roughly that order and roughly in the first hour.
Choosing the light comes down to two questions: which colour, and does it go in the water or above it.
Green or blue fishing light?
Both work. The physics is that green and blue are the colours water absorbs least, so they travel furthest and light the biggest volume. Of the two, blue goes further in genuinely clear water, and green holds up better the moment the water has any colour to it, which on most coasts and in most bays is most nights.
That's why green is the default and the colour most lights are sold in. Blue is the right call on a clear offshore night or over a clean sand bottom in calm conditions. If you fish one spot, ask what the regulars run there before you decide, because local water decides this more than theory does.
White light works too, and it's what your dock light already is. It attracts bait less selectively and lights up the surface, which can push the fish you actually want deeper. If you're buying a light rather than using the one on the dock, buy a colour.
Submersible, dock-mounted or flood?
| Type | Where the light goes | Best for | Power |
|---|---|---|---|
| Submersible | In the water, on a cord | Concentrating bait at one point below the boat or pier. The most efficient, since none of the light bounces off the surface | 12V battery or boat supply |
| Dock-mounted | Just above the surface, fixed | A permanent spot you fish repeatedly. Switch it on an hour before, leave it running | Mains, 120V |
| Flood | Above the water, spread wide | Lighting an area to fish and see in, rather than concentrating bait at a point | Mains, 120V |
Why is a submersible light more efficient?
Light hitting water from above loses a chunk of itself to reflection off the surface, more at low angles. A light already under the surface has nothing to reflect off, so far more of the watts go into the water column.
The trade is power. A submersible runs on 12V, which means a boat battery or a portable one, and it draws real current. The one we stock pulls around 7 amps at 84 watts, which a small deep-cycle battery sustains for a full session but a car jump pack won't.
The other trade is the cord. A submersible light on a pier has fifteen feet of cable between you and it, and every hooked fish wants to go around it. Keep the light off to one side of where you're fishing.
How long before the fish show up?
Give it an hour. The plankton gathers in minutes, the baitfish in a quarter hour or so, and the predators behind them on no fixed schedule. A light that's been on since dusk fishes better at nine than one switched on at nine.
Dock lights that run all night, every night, build a resident population of bait over weeks, which is why the best dock lights are the ones that have been there for years. If you own the dock, leave it on a timer.
Fish the edge, not the centre. Predators hold just outside the lit circle and dart in. A bait or lure worked along the shadow line gets far more takes than one dropped in the brightest water.
What about a spotlight?
A handheld spotlight isn't a fishing light. It's for finding the channel marker, the mooring or the ramp on the way in, and for the one time a year you need to see what's thrashing at the net. Four hundred lumens does that without destroying everyone's night vision on deck. Don't aim it at the water you're fishing.
What we don't stock
Battery-powered portable fishing lights, the kind with a built-in lithium pack you throw in a kayak or carry down a pier, and the larger multi-head dock arrays. Both exist and both are good for what they are. The lights we carry are the wired kind, which are cheaper per watt and last longer, at the cost of needing a battery or a socket nearby.
Also worth saying: some waters restrict lights, and some marinas restrict dock lights. Check your own rules before mounting one.
Common questions
- Does a green light attract fish in freshwater?
- Yes. The plankton-to-bait-to-predator chain works the same way in a lake. Crappie under a green light off a dock is a whole style of fishing on its own.
- How deep should a submersible light hang?
- A few feet down is usually right, enough that the surface isn't lit up and the light is actually in the water column. Deeper in clear water, shallower in murky water where the light won't carry anyway.
- Can I run a submersible light from my car battery?
- Technically, but a light drawing several amps for hours will flatten a car battery you then need to start the car with. Use a separate deep-cycle battery.