Those little red flags

I see some photos of boats on cars have red flags on the back. Are the red flags law? If you are caring two boats do you need one for each boat or just the one that sticks out the back the furthest? Do you use them? Who makes a good one if you do?

Laws vary by state, but generally if you are hanging 4’+ from the rear, it requires a red flag.

I have used everything from a red piece of plastic, to a bandana, to a shop rag. I recently bought one from midnight seamstress when I ordered canoe covers. It has a nice loop that makes it easy to tie off securely.


I don’t usually use a flag when on the roof, but always when trailering. And if I leave the car parked with a kayak on the roof, I tie a flag to whichever end of the kayak sticks out from the parking space. While hiking, I found an old bright red runners singlet (shirt) which makes a good flag. You can loop the arm holes over a kayak rudder or attach a tie through the arm holes.


I like this one from Seals:

Seals Sprayskirts - Travel Safety Flag (

I like it because it is durable, compact (narrow), easy to attach to the kayak, and a reasonable price. I put one on each kayak, as we usually carry two. I am not sure what the law requires, to me it is just assurance that the driver behind me will know I have something overhanging.

and I got it from:

The River Connection, Inc.
9 W. Market St.
Hyde Park, NY. 12538
845-229-0595 main
845-242-4731 mobile
Main: []
Store: []

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If you are over the legal length of the vehicle, you need to flag the load or if you are running at night you need to put a light on it. Doesnt matter if it is lumber, kayaks, or pipe. Look at your state regs.
When I had a 8’ bed PU and put the 17’ canoe or kayak in the bed, it is flagged. Now that I have the short bed (6’8") and plan to haul farther towing a camper, I built a rack that puts the kayaks a lot more fwd, so they dont need flagged.

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Florida has the 4’ overhang law. If something, anything, hangs 4 feet or more past the bumper, it must be flagged

The laws for flagging and oversized loads tend to be really byzantine and vary by state . They are really designed for commercial vehicles and are usually overkill for a cartop boat. To be safe and protect my boat and wandering pedestrian I always use some sort of flag whenever I’m carrying something that extends more than two feet beyond the ends of my vehicle.

In all my years of carrying rooftop loads such as 18" kayaks, 21’ lengths of steel pipe, and 40’ extension ladders I’ve never been stopped. It is probably different for large commercial vehicles that go through weigh stations or are sometimes stopped for random roadside inspections.

All bets are off if your overhanging load is directly involved in an accident and is not properly flagged and secured.

Federal lay allows up to 3’ in front, 4’ behind, and 4" from the side of the vehicle before flagging is required. Beyond that state regulations vary and can be measured from the ends of the vehicle or from the nearest axel. The size, type of flag, and nighttime lighting requirements also vary.

All that being said I’ve never heard of someone carrying a car top boat that has been ticketed for not having a flag, although I’m sure it has happened. Having a flag that is not officially approved or not lighted at night is probably even more uncommon.

Getting ticketed or not isnt how I measure whether or not I do something like flagging.

What is an “officially approved” flag?

A flag that complies with all federal and state regulations in terms of size, color, method of displaying it, and any additional requirements such as if used at night.

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There is no officially approved flag, that’s my point. There are some requirements (which I believe are quite minimal),so it is up to the user to ensure they are meeting those requirements.

"Warning Flags and Lights

An over-width or over-length vehicle/load combination requires bright red or orange warning flags (daytime) or amber and red lights (at night) at the extreme corners and extensions of the load. Flags must be securely attached to the load by one corner or displayed on a flag staff. Flags must be either 18-in. square or 12-in. square, depending on state requirements. Flags should be clean and in good condition."

On the sterns or our 16’ and 18’ kayaks we use several 3’ strips of yellow, red, and orange 1" nylon webbing. Does the job of making the boats very visible, but is obviously not in compliance with the federal or state regulations.

This is the official traffic law where I live in Alberta, Canada:

"If a vehicle’s load extends 1.5 metres (5 feet) or more beyond the rear of the vehicle, the following is required:

  • During daylight hours, a red flag should be attached to the end of the extension or load. The flag must be at least 30 centimetres (one foot) long on each of the four sides of the square.
  • At night, a red light must be attached to the end of the extension or load."

I use a couple of those Seals flags too.

My kayaks don’t overhang my SUV by more than 4’ and I don’t use the flags for local, 1-2 miles trips to the local boat ramps but if we’re taking a trip, especially overnight or with a lot of highway driving, I use them.

And I just used them today to bring home six pieces of 16’ moulding back from Home Depot! :grinning:

I use the free flag stuff from the local Home Depot. Its red plastic and there is a stand at the exit where you can tear one off. The stand also has poly rope and a blade to cut it.

I tie a piece of the HD plastic to a plastic carabiner and clip that to the stern. The plastic doesn’t hold up for long so get two.

There are minimum size requirements for flags I believe it’s 2’ x 2’ . You have state DOT regs then you have federal regs.

I use a daisy chained red strap on the back of boats on roof, often one that lives on the boat all season and I just tuck it under deck rigging.

It is a pass to legal requirements but at least as much so I can safely back up. I leave the strap long enough that I can see where the boats end to park facing out in lots. So the ends of the boats are not where a car can clip them off. Makes for a much more relaxed post paddle meal.

I know.

As to getting pulled over, you likely aren’t going to get pulled over for a wrong flag unless there is an accident, you make yourself a object of attention like a flat tire, or you do something stupid. Same as the overloaded pickups with fire wood in them or people not paying the higher class registration. You are good until you cause a problem, then you are going to be reamed.


Yep. To warn that the load is overhung. In Indiana, a red flag must be used if the load extends more than 3’ from the vehicle’s rear bumper. I keep one in my SUV.