Cartopping kayaks

[josko]

Why do we always carry kayaks bow-forward on roof racks?

[rfolster]

Aside from superstition, I would think aerodynamics would be top of the list.  The cockpit coaming slopes downward front to back, generally allowing air to go above the cockpit, and any air getting down in should slide back out the seat and bulkhead behind.  Facing backwards, the raised front of the coaming would force air to build up in the full volume of the cockpit.  I am sure there is plenty of turbulent drag from the wind curling around the front of the coaming and into the cockpit, but I would think it should be less than a direct scoop into a dead end.  Cockpit covers should reduce this drag either way, but I would assume less chance of imploding when bow forward.  I also think that most kayaks have a more gradual taper from bow to cockpit then stern to cockpit, although probably minimal.

[kate]

When I had a plastic Avocet, I always car-topped it upside down and backwards. Strongest point was the coaming so it made sense to let that sit on the crossbars, and as Rob said, the aerodynamics were more favorable if it was backwards (opposite of how it would be if right side up). I got scolded now and again about superstition - bad luck - but I had a lot of really good luck with that boat. Did the same thing with my whitewater boats. Rain didn't get into the cockpit that way either.

Kate

[Ken]

Through lack of attention, I've loaded my kayak stern forward.  I always tie it down with the rack bars lined up with the  fore and aft of the cockpit.  With it backwards, the length of the kayak doesn't line up as well with the car as well.  The bars are behind the fore/aft center of the car and the cockpit is behind the fore/aft center of the kayak.  So bottom line, less yak hanging off the back if I load it forwards.  FYI, the car in this case is a Toyota Venza mid-sized crossover SUV.

 

-Ken

 

[Pintail]

<When I had a plastic Avocet, I always car-topped it upside down and backwards. Strongest point was the coaming so it made sense to let that sit on the crossbars, and as Rob said, the <aerodynamics were more favorable if it was backwards (opposite of how it would be if right side up)>

This is just wrong, Kate -- with all due respect.  The laws of aerodynamics apply to your kayak on the rack in the same manner as when you fly your aeroplane upside-down, regardless!  Read Rob's post again: that is not what he wrote.  Forwards-facing is <always> better -- <fluid> dynamics...

Regards, CG

 

@Ken (with all due respect to you, as well): What is a "yak"?  I always thought it to be a four-legged transport animal?

Edited July 4, 2019 by Pintail

[kate]

CG,  Perhaps I've used terminology incorrectly, but I did not make a mistake about how air moves over the kayak when upside down and backwards. Putting it forward-facing would force air to lift up the bow which would be upward pointing because of the slant of the cockpit.  Backwards-facing leaves the stern sloping downward toward the front of the car, which lets air travel easily over it as the car moves forward. Try it with an Avocet sometime and you will see that I am correct.  

All bets off for how to carry a yak on the rak.

K

[PeterB]

There is much to be said for cartopping a kayak upside down. Right side up definitely presents a higher profile to the wind ,   ; I know because I often turn my boat upside down because only then does it fit under the narrow roof of the parking garage I must use now and then . It would stand to reason that that  lower profile means less wind resistance, and can't be a bad thing.  Otherwise, I suspect that there may be some  difference in  aerodynamics and air flow between backward and forward but it is probably nitpicky, not hugely significant. Its a kayak strapped to a car, and we'll all get there if it's  well strapped r secured to the car.  I'm inclined to think that,  all told, superstition and custom (like passing to the right at the dinner table , it's just done that way ) are the biggest reasons kayaks are carried bow forward.