Boat Trailer Lights – Your Options & The Law

There are some important product feature options to be considered as you make boat trailer light selection decisions. But, the first considerations are legal ones. The second portion of this article addresses boat trailer light options after the legal requirements are met.

The Law

From a legal perspective, a boat trailer is primarily grouped into one of two categories—boat trailers less than 80” wide and boat trailers more than 80” wide. However, additional illumination is required for trailers more than 30’ long regardless of width. So, what is required?

Your Options

Combination Trailer Lights

What? How many boat trailer lights do I need on my trailer? While you must have lights and reflectors that achieve all the above-listed functions, combination lights are commonly used, significantly reducing the number of required components. For example, combination lighting units often serve as brake lights, taillight, turn signals, rear lights, rear side marker lights, and rear side reflectors. Likewise, front side marker lights and front side marker reflectors are commonly grouped together as front clearance lights.

How do you know which functions a combination trailer light serves?

While DOT on the light's lens indicates that the device meets the US Department of Transportation requirement, a Society of Automotive Engineers (SAE) code on a combination light's lens will tell you for which functions the light is designed.

Incandescent or LED Boat Trailer Lights?

LED trailer lights have become the new standard. Their advantages include that they:

• Draw a fraction of the amperage that incandescent lights draw
• Operate at cooler temperatures
• Last longer
• More resistant to shock and vibration
• Typically brighter than incandescent lights
• Illuminate 2/10 of a second faster – which equates to 18′ when traveling at 65 mph
• Some LED's are offered in voltage operating ranges allowing the lights on the trailer to operate regardless of whether the vehicle is putting out 12v or 24v.

Until fairly recently, the primary drawback of LED boat trailer lights was that they were expensive – commonly more than double their incandescent counterparts. However, this has changed and LED light pricing has come down substantially.

Are Submersible Trailer Lights Necessary?

For trailering and launching a boat, submersible trailer lights are necessary for the simple and perhaps obvious reason that the rear of the trailer, including your clearance lights, will be partially underwater.

You may be asking yourself why this is even a discussion point. The trailer lights and trailer light kits you can find at most hardware, home improvement, or farm and fleet type stores can cause confusion. It is important to realize that these products are general trailer lights that are not submersible. They are great if you are hauling a utility trailer, a trailer with snowmobiles, or other non-marine applications where submersible lights are unnecessary.

For a boat trailer, non-submersible trailer lights will not be long for the world after one or two boat launches.

Interested in learning more about keeping your boat trailer safe? Check out these articles:

Boat Trailer Checklist for Season Breakout

Selecting & Installing M-Y Wedge Transom Supports

Tips to Securely Trailer Your Boat

Frequently Asked Questions About Boat Trailer Lights

Do you need special lights for the boat trailer?

As per the law, trailer light requirements are defined based on the trailer size. Hence, trailers that are 80 inches wide or less must be equipped with tail lights, stop lights, turn signals, side marker lights as well as side and rear reflex reflectors, while boat trailers above the range of eighty inches must have additional lighting for better definition and determination of their shape at night.

Can you use regular trailer lights on a boat trailer?

Ideally no. After all, regular incandescent bulbs are not built to last underwater. Waterproof trailer lights with incandescent or waterproof LED lights are highly recommended.