How to Tie Down a Kayak on a Roof Rack

Secure your kayak at both roof-rack crossbars with cam straps, then attach bow and stern lines between the boat’s ends and the vehicle. Tighten the straps until snug, check that the boat cannot shift, and recheck early in the drive. Follow your boat and carrier instructions for positioning and strap routing.¹²

This page summarizes published safety guidance. It is not a substitute for instruction, and conditions on your water may differ. Check the current rules for the state and water you paddle.

Key Takeaways

Check the vehicle, rack, and carrier limits before loading. Include the rack, carriers, and kayak in the roof load.²
Use two cam straps, with one securing the boat at each crossbar. Follow your carrier’s routing instructions.¹²
Attach both end lines for this procedure. Keep them snug, not overtight, and follow your carrier and boat maker’s tension instructions.¹³⁴
Secure loose strap ends, check for movement before departure, and inspect the attachments during the trip.²³

What you need before loading

Your roof rack must fit your vehicle and be installed according to its maker’s instructions. Crossbars are the bars that span the roof from side to side. Roof rails run front to back; they are different parts. A carrier is the support mounted on the crossbars that holds the boat, such as padded cradles called saddles or a J-shaped cradle.⁵¹

Check your vehicle owner’s manual and the rack and carrier instruction sheets for load limits and minimum crossbar spacing. Thule’s TOP DECK requires load bars at least 24 inches (610 mm) apart; follow the spacing requirements for your equipment.³ Account for the rack, carriers, and boat together, and stay within every applicable limit. Use the boat and carrier instructions to confirm their compatibility and the boat’s travel position.²⁶

Have these ready:

Two cam straps. A cam strap is a flat strap with a small clamping buckle, called the cam. You feed the free end through the buckle and pull it tight, and the buckle grips it. You use one strap over the kayak at each crossbar to hold it down.¹²
Bow and stern lines. The bow is the boat’s front; the stern is its back. These lines connect the boat’s ends to secure attachment points on the vehicle. Use water-resistant nonstretch rope or, if your boat maker permits them, purpose-made ratcheting rope lines. Ratcheting lines tighten when you pull the free end through a mechanism called a ratchet. For Delta kayaks, choose the nonstretch rope option.¹⁷
A towel or loading mat. Protect the roof edge during loading and avoid contact between the kayak and the car.³

How to secure the kayak, step by step

There are four parts: set the boat on the rack, strap it down at both crossbars, add the bow and stern lines, then check that nothing moves.

Inspect the rack and straps.

Check that rack knobs, bolts, screws, straps, and locks are securely fastened. Inspect the equipment for wear, corrosion, or fatigue, and replace worn or frayed straps before use. Make these checks before every trip.³²

Read your carrier’s routing instructions before loading. The crossbar method below follows REI’s guidance, but some carriers require a different strap path.¹²
Load with help and position the boat.

Clean the underside of the hull, the boat’s body. Protect the roof edge with a towel or loading mat. With a partner, lift by the hull, use your legs, and set the boat down gently on its supports.³¹

Center the kayak front to back between the crossbars and align it with the vehicle. Follow your boat and carrier instructions for which side faces down.¹⁶

For example, Eddyline permits its sit-in kayaks—boats with a cockpit, the opening you sit inside—to travel with that opening facing down, sideways, or up with suitable carriers. Its sit-on-top kayaks, which have an open seating surface, travel with the top surface facing down on padded bars. These are Eddyline’s instructions, not a rule for every kayak.⁶

If rain threatens, Wilderness Systems advises carrying the kayak upside down if possible, or sealing the cockpit with a cover if it cannot ride upside down. Water collecting in the cockpit adds to your roof load, and Wilderness Systems warns that a kayak heavy with water can become dangerous.⁴
Route the first cam strap at a crossbar.

For REI’s crossbar method, place the buckle beside the kayak, just above the first crossbar. Pass the free end over the boat to the opposite side of the vehicle, then underneath that first crossbar. Bring it back over the kayak to the buckle side, pass it underneath the same crossbar again, and feed it into the buckle. Both passes go under the first crossbar; the second crossbar gets its own strap in step 4.¹

Both passes beneath the crossbar must stay inside the points where the bar attaches to the vehicle. This keeps the strap loop within the bar’s supports.¹

Follow your carrier’s own routing instructions where they differ. For example, Thule’s TOP DECK routes straps under the crossbar, says never to thread them through the saddle, and warns against putting strap pressure on the cockpit rim or other unsuitable boat parts.³
Tighten snugly, then repeat at the second crossbar.

Press the cam buckle open to feed the strap through, then pull the free end to tighten it. Repeat the correct routing at the other crossbar so the boat is secured at both locations.²¹

Tighten until snug, without changing the boat’s shape.⁶⁷

Secure the excess strap ends so they cannot hang loose. Eddyline warns that driving over a loose strap end can seriously damage both the kayak and the car.²⁶
Attach the bow line to secure anchors.

Use secure attachment points on the boat and vehicle, as your equipment’s instructions specify. Yakima’s instructions name a secure boat handle or rescue bar (a grab bar on the boat) and metal vehicle points such as a metal bumper surface, a towing loop or a hole in the vehicle frame.²

If your boat maker permits ratcheting end lines, follow REI’s purpose-made ratcheting rope method: hook the line to secure points on the boat and vehicle, then pull it snug. Use a suitable hood-loop anchor if needed, following its instructions. Avoid plastic vehicle attachment points. Tie off the loose rope below the ratchet.¹
Attach the stern line snugly, without overtightening.

Repeat the end-line attachment at the back of the boat and vehicle. REI recommends end lines, especially for freeway travel or wind. Thule’s TOP DECK instructions require both bow and stern attachment on every trip.¹³

Keep the end lines snug, not overtight, and follow your carrier and boat maker’s tension instructions. Wilderness Systems specifies minimal tension for its boats because these lines supplement the rack tie-downs; excessive tension can distort the boat’s shape.¹³⁴
Check for movement before driving.

Try rocking the kayak to check for movement. If it is loose, correct the strap routing or tension and check again. Complete this check before setting off.²

Check all fittings and connections, including the end-line anchors. Confirm that excess strap and rope ends are secured.⁴²¹

How tight should the straps be?

Aim for snug straps that hold the boat securely during the movement check. Do not tighten them until the hull bends or changes shape.⁶⁷²

The damage warning depends on the material. REI warns that excessive strap tension can deform plastic hulls and crack fiberglass. For Delta’s thermoformed plastic kayaks—boats formed from plastic sheets—the maker warns: “Do not use ratchet straps as they can easily be overtightened and damage your kayak.” Delta recommends 1-inch-wide, 8-foot-long cam straps with a proper cam-lock buckle for these kayaks, but warns against tightening them until the boat’s shape distorts. Its manual does not publish a numeric tension or pull-force limit.⁷ For Delta’s bow and stern lines, choose REI’s water-resistant nonstretch rope option.¹

Wilderness Systems gives a further warning for its boats made from polyethylene, a type of plastic. Check your boat maker’s material specifications to identify whether yours uses it. Warmth makes this material more flexible, and leaving a boat tightly strapped to a rack for days can temporarily deform it where it rests on the supports. That warning concerns sustained pressure and heat.⁴

What to check during the drive

Account for the kayak’s added height and width at low clearances, including branches, bridges, and parking garages. Roof cargo also changes how your vehicle handles, brakes and reacts to side winds, so adjust your speed to the load, the road and the wind.³²

Plan an early stop to inspect the load. REI recommends stopping after about 15 minutes and tugging on the kayak to check it. Wilderness Systems advises checking fittings and connections shortly after departure. Follow your equipment’s recheck instructions too.¹⁴

At stops, inspect the rack, straps, end lines, and attachment points. Recheck wet straps periodically during travel, too. Correct looseness without tightening enough to distort the boat. Thule calls for fastening checks at stops, and Yakima calls for periodic load and attachment checks during travel.³²⁷

After unloading, release the transport straps. Wilderness Systems warns that keeping straps tightly wrapped around a boat for extended storage can deform it.⁴

Does an overhanging kayak need a flag?

Check before driving if your kayak extends beyond the vehicle. State vehicle codes can regulate projecting loads (cargo extending beyond the vehicle) and require warning flags, lights, or markers that reflect light to make the overhang visible. Thule directs users to check applicable state and local laws.⁸³

Look on your state Department of Motor Vehicles or State Patrol website for “projecting loads,” “load overhang,” and “flags and lights.” Follow its link to the current vehicle code. Read its marking thresholds, measurement points, required marker sizes and placement, and lighting conditions, including any linked lighting rules. Check the states along your route.⁸³

Do not treat a federal commercial-vehicle rule as permission for your private car. The marking requirements in 49 CFR §393.87 apply to commercial motor vehicles; they do not supply a universal private-car overhang allowance.⁹

Where next

Use the care and transport guide to plan the rest of your boat care. After unloading, follow how to store a kayak.

For related topics, look for kayak roof racks compared (coming soon), roof load limits explained, lift-assist and loading a kayak alone (coming soon), and kayak trailers (coming soon).

https://www.rei.com/learn/expert-advice/transporting-kayak-canoe.html ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸
https://assets.yakima.com/product/instructions/8004084/1 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶
https://www.thule.com/-/s/approved/std.lang.all/38/26/363826.pdf?rev=1.8 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³
https://www.confluenceoutdoor.com/pages/wilderness-systems-faq ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷
https://www.thule.com/en-us/articles/guides/what-can-i-use-my-thule-roof-rack-for ↩
https://eddyline.com/pages/faqs ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶
https://www.deltakayaks.com/wp-content/uploads/2018/10/2018-delta-kayaks-owners-manual.pdf ↩ ↩² ↩³ ↩⁴ ↩⁵
Washington State Legislature, RCW 46.37.140 (Washington law; check your own state’s current code): https://apps.leg.wa.gov/rcw/default.aspx?cite=46.37.140 ↩ ↩²
https://www.ecfr.gov/current/title-49/subtitle-B/chapter-III/subchapter-B/part-393 ↩