Go Joe Current and wind affects

Baconyoulikeapig · Since 27 Jun 2009 26 Posts

Will a Go Joe really help that much at a place such as SI where there can be a moderate amount of current as an opposing force to the wind? And should it have any problems flipping a LF proof 151? Thanks.

Nak · Fri Jul 03, 09 11:23 am

Haven't used one, but no reason why it shouldn't work well on anything. Even if it doesn't flip it over it still will expose a lot of surface area to the wind. You'll still need to be able to know how to bodydrag, but it should be tons easier to get to.

pauls · Since 20 Jun 2005 564 Posts Northern Portugal Addicted

go joe is no substitute for learning body dragging but a lot safer than a leash. Yes they work at places like Sauvies and will either bring your board back to you or make it much easier to spot for recovery. Only problem is once you start using one it becomes a bit of a crutch and you won't want to stop BUT when you start wrecking hard from jumping and swell riding they start breaking which is a hint your ready to live without it. And don't forget to put your phone # on your board.......

paul - reformed Go joe user

Baconyoulikeapig · Since 27 Jun 2009 26 Posts

I do agree that knowing how to body drag is important. I was just looking for a way to slow the board drift down as it sometimes takes me 6 or so tacks to get back to it.

And yes, name and number were the first things that went on my board. Wink

Thank you.

pdxmonkeyboy · Fri Jul 03, 09 12:42 pm

u need to be taking longer tacks away from your board. 6 tacks is allot of tacks even if your board is 50 yards away. Use you arm more and you should rocket up wind.

Scribble · Since 18 Nov 2005 636 Posts NoPo Addicted

wiseguy2 · Since 22 Feb 2009 89 Posts

Maybe I'm nuts but I think there is a lot of confusion about the relationship between the current and the wind.

The current doesn't affect anything when it comes to recovering your board. If the current is x miles per hour (where x is zero, a lot, or a little) the kiter and the lost board will be affected equally by it. Both will move the same apparent distance (xt) while the board and rider are separated.

So, the only factor of importance is the wind. The go joe will help the board catch more wind so that it will keep up with the rider who is, no doubt, being dragged down wind by his kite (before he starts body dragging up wind).

That's it. The current is a non-issue. In fact, the only way the current factors in is by the facts that a) it creates apparent wind and b) it helps you from going to far downwind (if the wind and and the current are in opposite directions).

Diggy · Since 25 Nov 2006 342 Posts Gorge to Coast Obsessed

Reaper356 · Since 10 Dec 2006 781 Posts Salem / LC Oregon Opinionated

Really overpowered situations make me worried about losing the board. You get hucked and you might lose site of it; or you can't make enough progress while keeping an eye on your board - again you might lose it.

99% of dragging situations work out fine.

pdxmonkeyboy · Fri Jul 03, 09 8:03 pm

The current plays a huge roll in board retrieval if your board is in the water and your kite is in the air (in the summerr west winds) the current is carrying your board away from you an the wind is pushing you away from your board. If you think that the current doesn't have an affect on your board go kite at rufus or the other spot that won't be mentioned.

wiseguy2 · Since 22 Feb 2009 89 Posts

I really can't see how the current can affect the rider and the board differently (other than uneven currents as pointed out by a previous writer). Perhaps you can explain what is wrong with the following argument...

If you are in a high current region like Rufus, the board will go down river at some high speed say 10mph.

You also will go down river at 10mph. If you start flying your kite directly upriver (worst case scenario) in a wind of say, 18 mph. Your speed with respect to the shore will be 8 mph (=18-10) upwind. In one hour your board will travel 10 miles downriver and you will travel 8 miles upriver. The total distance between you and your board will be 18 miles.

Now, say, the current is 50 mph. And the wind is still 18mph. In one hour the board will be 50 miles downriver and you will be 32 (=50-1 Cool

miles downriver. Again the distance between you and your board will be 18 miles.

Unless, I failed highschool physics and also failed as a physics teacher, I can't see any reason that the current is a factor.

wiseguy2 · Since 22 Feb 2009 89 Posts

I really can't see how the current can affect the rider and the board differently. Perhaps you can explain what is wrong with the following argument...

If you are in a high current region like Rufus, the board will go down river at some high speed say 10mph.

You also will go down river at 10mph. If you start flying your kite directly upriver in a wind of say, 18 mph. Your speed with respect to the shore will be 8 mph (=18-10) upwind. In one hour your board will travel 10 miles downriver and you will travel 8 miles upriver. The total distance between you and your board will be 18 miles.

Now, say, the current is 50 mph. And the wind is still 18mph. In one hour the board will be 50 miles downriver and you will be 32 (=50-1 Cool

miles downriver. Again the distance between you and your board will be 18 miles.

Unless, I failed highschool physics and also failed as a physics teacher, I can't see any reason (other than uneven currents as pointed out by a previous writer) that the current is a factor.

genek · Since 21 Jul 2006 2165 Posts East Po KGB

Sounds like you didn't fail physics, but you failed the "How to avoid double postings" training class Wink

To quote other people "In theory, practice is the same as theory. In practice it is not."

Yes, in an ideal setup current shouldn't matter. In reality there's a ton of factors being overlooked. High currents probably cause more eddies and variability in different parts of the river. High winds (at Rufus, etc) tend to be gustier and probably not only cause more incidents where people separate from boards, but also jerk people downwind more any time you screw up.

Bottom line is you should learn to relaunch your kite well and body drag well and don't go dragging on the opposite side of the river from your board.

Oh, and you can always switch to boots if you don't wanna lose your board.

cosmodog · Since 06 Oct 2005 205 Posts Stoked

If you are really overpowered (esp with older kites) it can be harder to get your board when there is current. Once you are pulled a good bit out of the water, the current is not helping much, but is still taking your board away. Disclaimer: I passed physics, but just barely Very Happy

wiseguy2 · Since 22 Feb 2009 89 Posts

Yes, I have changed my mind... (like the bumper sticker says... If you can't change your mind, are you sure you still have one.)

The current is a factor in both theory and practice. Due to the "apparent" wind, the force on the kite will be greater.

Say, there is no current. In a 10mph wind, you would move, say, at 8mph with respect to the shore. (The water slows you down.)

With a current of, say, 5mph. The apparent wind is 15mph and the force would be greater. So, you would move through the water at, say, 14mph. Meanwhile the current is 5mph, making your net speed with respect to the shore of 9mph. The board will move downstream at 5mph, so your speed with respect to the board will be 14mph which is much worse than the situation where there was no current.

pdxmonkeyboy · Sat Jul 04, 09 12:32 pm

I knew that something was not right with your math based on real world experience. If your in a ripping current your board DEFINITELY heads downstream faster than in a slower current. There are two objects with forces acting on them the board is only affected by the wind while the kiter is affected by wind AND current. The current in this case is not subtracted from the forces on the kite, it is ADDED as current increase the amount of apparent wind on your kite. I.e. in 18 mph winds your more lit in greater amounts of current because the force of the kite is increased by the current as you the kiter are not stationary. You see in the equation below that the force of the current is essentially negated because even though the force on your kite is greater, your position is changing as you ARE flloating downstream.

In your example, the board has one force acting on it, the current at -10 mph.
The kiter has two forces acting on it +28 mph of relative wind (wind plus current) and current +18 (APPARENT wind ( + 28 ) - current(-10 )). So in an hour, your board will travel -10 miles while you will travel +18 miles meaning that your 28 miles apart.

in 50 mph current
board = -50
rider equals +68 - 50 = +18 (you can see that the force on the kiter is essentially just the wind).

So in this example, your board will be 50 miles downstream and you will be 18 miles upstream for a difference of 68 miles.

This is a way oversimplified approach as the true problem is not as simple "there are two objects traveling at different speeds " as there is a multitude of different variables. For instance, if one force vector is heading east (wind) and the other (current) is traveling east..how can you ever manage to retrieve your board? Also, the drag on your body negates much of the force of the wind in a very non-linear way (much like drag on your car where in the drag at 50 mph is several times greater than the drag at 25- not just twice).

Regardless, I would love to see a physics expert tackle the problem. Maybe I'll lob it to my father in law who is a plasma physicist. The bottom line is this..in higher currents, your board goes by by much faster than in slower currents. Don't believe me, thats fine. See you in the lost gear section. Smile

Slipin Lizard · Since 23 Sep 2005 88 Posts Hood River, Oregon

Man, you guys must have gotten cooked in the sun or something... you're making it all way too complicated and apparent wind has nothing to do with it. Your kite offers a significant resistance against the wind, and therefore tends to slow you down against the pull of the current. Your board does not. That's why your board floats faster down the river than you and your airborne kite. Its also the working prinicpal behind the Go Joe, it simply gives the board more wind resistance than without.

Apparent wind is a pretty complicated formula, but it doesn't mean much to kiters or windsurfers in the Gorge unless you are racer or designer. It's a common mis-conception that when the current is stronger, the apparent wind increases for kiting/windsurfing. However, this would only be relevant if you were moving steadily downriver with the current on each reach. In that case, yes, you would factor in apparent wind but both of you are doing totally fuzzy math that gives it a far higher number (and therefore importance) that in reality. We tend to go out on the river, and come back to where we started. Every time we're reaching upwind, the apparent wind will increase. Everytime we go back downwind, the apparent wind will decrease. So for any given session, you're going to experience variation in apparent wind.

Now quit worry about it and go kiting!