cartop on prius without racks

Can you safely put an 18’ kayak on a prius, with only foam blocks and straps (no rack) for an 8 hour drive?

I don’t think I would…
Since I own a Prius, I’m pretty familiar with it. I carried a canoe one time on mine with foam blocks, but it was only for about 25 miles on back roads where I didn’t get up much speed nor encounter big trucks going the other way. The problem with the Prius is in the length and shape of the roof. You can’t really separate the foam blocks far enough forward and back to get four widely separated points, so mo matter how well you tie down the front and back ends, the ends still yaw quite a bit from one side to the other. I wouldn’t want to be carrying it that way on high speed highways.

I bit the bullet and bought Thule racks for mine, although I seldom use the Prius because I also have an SUV with racks that carries the canoes much more easily.

Foam blocks have their use, but not for extended freeway travel. Having the yak come off the car and damage it is bad, having it damage someone elses car will pay for the racks thousands of times over.

Bill H.

perhaps I should rephrase
Is it safe to make a single trip with foam blocks, double bow and stern lines (vee-ed to each corner of the bumper), and straps through the doors?

It’s not a question of whether we buy a rack for this car. It’s a question of whether we find a different way to get this boat home.


I think it is safe for the boat
if if is sturdy enough and you do not strap it too tight. It’s very unlikely that it will fall off if you tie it properly.

You may get rub marks on the car paint/clear coat, though … But I think that’s avoidable too - just clean all dust carefully and perhaps use masking tape or some other easily removable substitute stuck to the car top under the foam blocks.

You may want to go out and push down with your hand the roof in several areas to see if you can find suitably sturdy areas - on my '02 there are some places that are quite flexible and if the sturdy areas are not well positioned you may have a wobbly or lop-sided ride…

A possible addition

– Last Updated: Sep-20-10 6:16 PM EST –

I can't answer your question, but if you decide to transport such a long boat on such a short, curved roof, it might be good to add some kind of sticky interface between the hull and the foam.

Maybe try something like a very grippy yoga mat, or even the coated-rubber mesh mats that department stores sell for use underneath dishes stored on shelves. I once had a sticky rubber fake chamois rag sold at an auto supply store. It did not feel like chamois at all (so don't go for a Chameez or similar), but instead had a leathery-tacky textured surface.

Another possible sticky interface is a sheet of silicone intended for use in the oven.

The foam blocks are pretty decent, but since they don't grip around the hull the boat is slightly more prone to slipping a bit. I have used them on the trailer crossbars and keep a set around for backup use.

I have a prius and a yakima rack, which works fine–I’ve used it for 6 years without a problem, and just finished a month long trip with it on top (well, most of the time the kayak was in the water, but you get the idea).

A couple times I haven’t had the rack with me when I wanted to move my kayak ( a 17ft long BBK valkyrie) with the prius. Rather than tie foam blocks to that curvy roof, I roll the passenger window down, take the passenger seat headrest off, and put the passenger seat back all the way down. I lay the back seats down as well. This opens up quite a long carrying space in the car, and most of the 17ft kayak can fit. I place the first 8 inches of the bow out the passenger window, resting on the passenger mirror. I angle the kayak back, and tie the stern of the kayak down with a nrs strap (using the convenient metal loop in the back of the hatchback–I think that’s there for the netting). I also tie the hatchback down (gently, with a bit of rug as padding), so it doesn’t bounce. I’ve never driven very far like this, but it works fine for short drives. 8 hours? Who knows.

yes you can
If you use straps through the doors the worse that a passing truck or emergency swerve would do is make the boat twist a bit off center. I know this from years of transporting my sea kayaks in the same manner. I have a flat, but equally short or shorter roof than a prius and can’t spread the foam blocks far apart either, but I’ve connected them to each other with plastic conduit and glue so they won’t wander. I also added tie down straps under the edge of my hood to keep at least the bow more stabilized in strong winds. Make sure the straps are long enough to double wrap the hull and cinch it tight to the roof. This will keep it from sliding or torquing to the sides. Just don’t leave a plastic boat cinched tight for long in the sun. Over the years the blocks and especially the straps have lightly scuffed the car paint, but it really isn’t bad and disappears after a good wax/polish job. Yes, you can cover the area in masking tape to temporarily protect it…


another shot with the hood tie downs

Besides loosing 200 hours worth of work in this boat and causing a serious traffic accident, I wouldn’t transport it in this manner if I wasn’t sure of it’s stability. btw, put a few twists in the straps to keep them from vibrating in the airstream.

How many local rds v highway?

– Last Updated: Sep-21-10 8:10 AM EST –

FWIW, the boat in question has a tremendously sturdy layup even with a few used dings if it is remotely like the one in our basement. So you can get some pressure on the straps.

phransis's post contains some measures that sound good and are well above what I usually see on boats transported in this manner.

One immediate thought is that highway speeds would be more punishing (and require more frequent stops to check) than local roads. How much of this trip will be on highways? If it is the route I am guessing, at best half.

I wouldn’t
but then I’m nervous with the boats in the rack on a long ride. We have got a Yakima system w/J bars for our Prius to carry our 18’ yaks. I am sure it is possible without, I don’t doubt other posters here; I just would be real nervous myself.

You tell me Celia, as I’m sure you know the route better than I do. My folks are in NYC, and I’m considering asking them to drive through Troy on their way back to our place.

What’s the best way for them to get from Troy to Ellsworth? Rt 2 to 495? Once they get to Augusta they’d get off the highway and take Rt 3, so that’s easy driving for the last hour and a half, but I’d think the first 5 hours or so would be basically highway speeds.

They normally have racks and saddles on their car, but . . . they removed them before they left. (doh!)

Hmm - mostly highway then
Best route is freebie 90 east to the Mass Pike to 495 and up - virtually all highway until about 30 or so miles from you. So much for that idea…

The other thing this means is that the special accomodations mentioned by phrancis above are not going to be likely, like gluing the blocks to be more solid etc. They’d be grabbing blocks from somewhere and doing their best in Troy with basic materials. And they (or the seller) would have to get some loops like from a fabric place to put onto the hood bumpers for the bow line(s).

I am thinking the only one who can answer this well is the seller. He’d be the last person to really vet how well the boat is attached under this scenario.

Do it correctly
You soulldn’t have a problem if you do it correctly. Strap the blocks to the kayak first, this will keep them from moving. Put a strap through the doors, and of course use bow and sterm lines. Pull the straps tight, and check them after driving a short distance. You’d be surprised how little road time it take lossen an improperly placed strap. And like someelse said, put a twist or two in the straps, a flat strap will buzz, and will drive you insane. I learned the hard way about that.

Go for it , (just kidding)
the worst that could happen is scuffed paint on car, busted up 18 footer laying on road behind you, or a major traffic accident caused by you. Is it really worth your cheap way of thinking? Sorry,I’m just with some of the others, that no matter how far you travel with a kayak or canoe mounted in this way ,it just “ain’t” bein’ responsible. Just like any other sport, investing in equipment is a requirement,if you want to do it right. Better now than later!

Oper is not thinking cheap
He is asking if it is possible to move a boat this way because he’d like to get one that is being sold from over 8 hours away, and the Prius idea is his closest option. It is at least worth asking for considered and reasonable feedback.

thanks for the input
Basically this thread is affirming my own range of concern/confidence in the arrangement.

I do tend to think it could be made to work, with plenty of care and well-placed straps. I’m hesitant to leave my parents (the ones driving this car) with the responsibility to make sure the load stays right for the trip.

I have some other options for the trip. Just trying to find the best one.

Haven’t done it, but have seen it done
several times and have to admit the kayak was solid. Just as described above:

1)firmly strap the boat to the foam blocks fore and aft.

2) lift the kayak onto your roof and ensure it’s centered right to left and your blocks are where you want them.

3) Open the car doors (and/or rearwindows), run the straps from the foam blocks thru the car (front and back) and add a couple twists in each strap. Snug these straps and shut the doors. Check the straps.

4) Attach your bow and stern lines.

5) Attach a flag to the stern, and fire up the car GPS.

Have them do a test drive, and check the attachments every so often.

I would not use this method in high winds, but in normal conditions, if it is tied firmly, it shouldn’t move. I prefer racks myself, but have seen this method used on highway driving (4-6 hours) in Florida a number of times.

Ship the racks!
You got the racks - ship them to your parents. Not sure about cost of such long item but if you have time, may be there is a reasonably priced shipping option (USPS parcel or UPS). Then you got “proper” racks…