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#BallOfSpray #lifeonthewater #waterski

Boat Driving & skier speed

BrentBrent Posts: 3,583 Solid Baller
edited September 2012 in Technique & Theory
Last night my friend Eric sent me the below e-mail & I asked him if I could post it here. Boat path seems to play a big roll in skiers success at 38off & beyond ,this opens a great discussion .


The goal of skiing is to maintain a constant speed at all times through the course – by the laws of physics ,this is the most efficient way to run a pass.
Many times when an experienced driver pulls a skier , it seems easy and slow for the skier, yet the course times were exact..Why does that happen ?..

Here is the explanation why we experience an easy time behind certain drivers....... and it proves that those drivers are actually driving CORRECTLY by the laws of physics and not just helping the skier unfairly with a “ ski school swerve”.

Below is the physics formula for why a boat driver’s direction of travel in the course from boat guide to boat guide is so critical for keeping the skier at a constant speed (avoiding accelerations and decelerations) as he rounds the balls. I drew it out on paper and simply put, if the boat is pointed away from the skier as he hooks up at the ball, this decreases the alpha angle which decreases the skier’s speed relative to the water. At short rope lengths this is critical to give the skier ample time to get set in a pull position after the ball versus pulling him off the ball.






Another way to write the equation is:

V2= V1 x Alpha/Beta

V2 is skier speed
V1 is boat speed
Alpha and Beta angles are explained above.

Simply stated, the skier’s relative speed to the water depends on the speed of the boat multiplied by the ratio of the boat’s angle to the rope(alpha) divided by the angle of the ski’s direction relative to the rope(beta). The skier is at maximum angle behind the boat (beta angle is high) and the alpha is low because the rope is directly behind the boat,,,,,but then the skier’s angle to the rope decreases(Beta decreases) as skier turn back toward the boat while the (alpha angle increases)......as a result, the ratio goes up and the skier speed will increase(according to the formula) unless the driver points the boat away to decrease the alpha angle. Conversely, if the skier keeps the ski going outward as long as possible (keeping the beta angle as high as possible), this keeps his speed relative to the water constant and slower despite feeling more load on the rope. Keeping outward direction as long as possible on the ski reduces speed on the skier and makes the pass seem slower. Unfortunately many of us try to ski a pass as narrow as possible because we get inpatient ......as a result the pass seems really fast because we never got good Beta angle !!!!!
That is why pointing the boat away from the skier is not cheating(even though the boat whitewash looks closer to one boat guide than the other)..... it simply keeps constant tension on the line and a constant speed to the skier. Anybody with little experience can keep a boat straight down a course, but with more experience driving we learn to minimize the Alpha angle at the right time.



EAS






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568 x 484 - 527K
Just a BOS ex-con tryin to stay outta trouble.
JMLVMI
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Comments

  • colo_skiercolo_skier Posts: 422 Baller
    Ok I'll bite, If the boat is turned away from the skier isn't the alpha angle in the diagram above increased? I probably don't understand the drawing correctly.
    Somebody made it look like I think I know what I am doing. I really don't and my account name is where I am and what I love to do. Squirrel!
  • ShaneHShaneH Posts: 4,901
    @Brent I disagree to some extent. I spent a lot of time with Becky Lathrop, Chad Scott, and Joe Darwin last year and earlier this year talking about my driving. One of the things I found, confirmed by the 41 off skiers I've been pulling, was that the skiers feeling of speed was more based on what the driver was doing as the skier crossed behind the boat. A driver who counters into a block as the skier is directly behind the boat feels slower. A driver who tensions the wheel(I am very hesitant to say points) the boat opposite of the skier at the apex feels softer. The two things together make a slow, soft pull. I think most people would be surprised at the intensity of the counter and block that the elite drivers are making with a 39 1/2 and 41 off skier.
    Shane Hill
    "If you are not capable of going through the gates, go play Shuffle Board."
  • E_TE_T Posts: 282 extraterrestrial trouble maker
    Angle alpha does decrease when the boat is driven from the skier
    E.T. phone home!
    I like reese's pieces
  • gregygregy Posts: 837 Baller
    I don't quite understand the point @Brent is making but I think @ShaneH and Brent are saying the same thing. Brent is looking at boat path and keeping that path at a straight line. It is necessary to "point" the boat at slight angles with respect to boat path inorder for the boat to continue in a straigth line down the middle of the boat guides.

    Even if the force applied by the skier at all alpha angles (different line lengths) were the same you would expect the counter steering by driver to increase at shorter line lengths (ie larger alpha angle) due to the fact that more force is being applied in a direction that will want to pull the boat off its straight path.

    Ok now in reality, the force the skier applies in extremely short line lengths is going to be greater vs. shorter lengths. All things consider the boat will be required to "point" in increasely greater angles off the straight line boat path so that it can follow that straight line.
    Gloersen
  • ShaneHShaneH Posts: 4,901
    The boat isn't required to point in increasingly greater angles as the line gets shorter. The intensity of the counter goes up, but the amount of counter in degrees of wheel motion doesn't really change. It's actually harder to driver a 15 and 22 offer because of the way the angles work out and the amount of counter required and where.
    Shane Hill
    "If you are not capable of going through the gates, go play Shuffle Board."
  • BrentBrent Posts: 3,583 Solid Baller
    I posted a friends thoughts,my thinking is not as in depth ,I just think a "straight" inflexible boat path does not help short line skiing. This is a great topic for the forum though. If it is the ski boat pylon that is watched to confirm boat path for records ,why don't they have a long orange bar sticking up in the air to make it easier to keep track of the path?
    Just a BOS ex-con tryin to stay outta trouble.
  • 6balls6balls Posts: 2,510 Crazy Baller
    If you watch the best, though, the boat path is terribly straight. I do agree with what is being said, but it must be very subtle. Done too dramatically and would be harmful.
    Dave Ross--die purple die
  • ShaneHShaneH Posts: 4,901
    The more I've driven over the last few years, the more I've learned that less is more. One of the first things Chad told me three years ago was that the wheel was too busy. Until an elite driver gets in the boat and starts telling you this stuff, you have no way of knowing.
    Shane Hill
    "If you are not capable of going through the gates, go play Shuffle Board."
  • gregygregy Posts: 837 Baller
    @ShaneH its been a long time since I've driven anyone less than 28off. So I can't draw from much experience, just trying to understand Brent's point. So Shane how much do you think the boat deviates from the Brents straight line path. And when you say intensity of counter do you mean degrees of angle of rudder rotation or the rate at which the rudder rotation is applied (or something else).

    Last time I drove for a skier at 38 or 39 was before speed controls. I remember fighting the throttle more than steering.
  • ShaneHShaneH Posts: 4,901
    @gregy When I say intensity, I mean the rate at which the rudder is moved. As the line gets shorter, the counter gets quicker. With some skiers, the amount of counter(ie the distance you move the wheel/rudder left or right) lessens as the line gets shorter.

    This is a great topic though. For me, the hardest thing to learn was blocking the wheel at center and holding the boat there. Honestly, it took Joe Darwin pulling Charles 2@41 at 36 twice and then Charles saying this is what I feel with you, this is what I feel with Joe/Chad/Becky. And then Joe and I compared. Obviously, Joe was better than me so I listened. And then what Becky and Chad had been telling me started to make sense. Funny thing was, the next chance I got to practice what they preached was at Joe's Record. Good thing was, I didn't pull anyone up onto the shore. :)
    Shane Hill
    "If you are not capable of going through the gates, go play Shuffle Board."
  • gregygregy Posts: 837 Baller
    I guess over countering the steering in the slalom course is kinda like over-correcting with a maneuver in a car - bad thing.
  • ShaneHShaneH Posts: 4,901
    Bingo! Also, wayyyyyyy too easy to over-correct or be busy with the wheel when you drive two handed. That's one of the first things I tell people.
    Shane Hill
    "If you are not capable of going through the gates, go play Shuffle Board."
  • 6balls6balls Posts: 2,510 Crazy Baller
    @shaneH, just curious on what goes on in the mind of the really good driver when some jock-o comes out there and hammers them after a bad 1 but scrapped out of the pass. I apologized to a driver last weekend...unfortunately not the first time : )
    Dave Ross--die purple die
  • webbdawg99webbdawg99 Posts: 603 Crazy Baller
    @ShaneH I am one of those guys that really prides myself in trying to be a good driver. And because of that, I'm always seeking more knowledge and understanding of how to become better. Will you please explain to me what you mean by the term "blocking"?
  • skibugskibug Posts: 1,541 Solid Baller
    edited September 2012
    @ShaneH is dead on! Shanes explanation is exaclty what I have been taught and practice; but, it takes a lot of time behind the wheel and a certain level of natural feel. When I first started driving correctly it felt very foreign.

    There are 2 actions that need to take place to give someone a slow and soft pull. You have to counter or point the nose of the boat away from the skier as soon as the pressure from the skier releases from the boat (or in some cases you need to anticipate it just prior to them releasing) to bring the boat back on center and then "catch" (block) them out of the ball. My mindset is point nose, straighten back on center, catch the skier....so maybe it is actually 3 actions.

    I can say this from experience driving elite skiers for the last 3 or 4 years and being coached by a very good, pro event Senior Driver. All this theory actually applies to longer line lengths as well; but, it is dependent on the skier. Each skier and speed is going to feel different and you will learn how to feel that out the more you drive. I pull everything from 30 mph -15' skiers to 34 mph -41' and one 36 mph skier at our lake. For the record, I feel It is easiest to drive at 36 mph. I actually have a harder time pulling the slower skiers because I have to tell myself not to "overdrive" the pass; especially when going from a 34 mph -39' man to a 30 mph -15' woman in consecutive sets.

    Some have a theory that there should be no driver input so that all is fair; meaning straight down the course with no "driving" to "help" the skier. This is a falsehood. There is no way you can drive striaght down the course when a skier weighing 200 lbs is pulling his guts out at -38'. If you mindset is to try and stay in the middle of the course; but, you do not employ the driving technique described above you will always be reacting (chasing) to the skier instead of staying ahead of them in the course.

    Another note for new and/or old drivers that want to buy in to this technique; you are not going to get it right away. That is OK. When I ski with a new driver that I explain this to and work on it with them from behind the boat; all I ask is that you "try your best".

    "Odds are you aren't going to make it all the way down the lake with perfect driving, especially if there is some scrambling going on behind the boat; but, if you can get me through 2 or 3 to start with it gives me a much better chance to run the pass".



    Bob Grizzi
  • skibugskibug Posts: 1,541 Solid Baller
    @webbdawg99, I will chime in and give you my definition of "catching" or "blocking" at the ball and see if @ShaneH can expand on it or agree with it.

    As with most technique, it comes down to practice, feel, and timing. For me, I try to anticipate the skier's hook up with the boat out of the ball and match my wheel input with the skier's input. It is then equivalent resistant thumb pressure against the wheel, resisting the skier's force on the boat; but, not driving away from the skier. It is almost on the verge of letting the skier "have the boat" or "pull it down".....but not letting that happen. The length of this resistance pressure on the wheel can and will vary by skier and by what is going on behind the boat. Picking up the feel for this comes from practice, practice, practice.
    Bob Grizzi
  • ShaneHShaneH Posts: 4,901
    @6balls Never had anybody apologize to me. lol. But the Kuykendahl Brothers both thank you at the end of every pass, which is kind of cool. I don't know about the good drivers, but when someone hammers me unexpectedly the only thing I think is "don't over correct!" You have a tendency to want to over correct to keep the boat from moving. But if you do, you then end up making it worse because you sling the skier outbound to the next buoy or drive into them at the next buoy causing them to lose the rope. It's kind of like a skier learning course maintenance. If you get behind you don't try and take it all back at once. Same with driving. If you get hammered, you almost have to drive normal. It's a game of inches.

    @webbdawg99 As the skier reaches the apex of say 1 ball, you pressure the wheel left just a touch. This moves the bow to the left just a touch. You're not moving the bow, you're pressuring the bow if that makes sense. Then as the skier loads, you move the wheel in a counter motion left. As the skier goes behind the boat, you center the wheel quickly and hold the boat. This is the block. The skier is now going outbound towards two and you are holding the boat perfectly straight and centered with just pressure against the rudder. This is where if you were to counter left, then right(thinking you need to counter the skiers movement outbound), you sling them into the next buoy. So you're wheel movements become Pressure-Counter-Center-Hold-Pressure-Counter-Center-Hold-Pressure-Counter-Center-Hold and on down the course. Also, don't forget that you have to counter the skiers pullout too. When you get into a rhythm with the skier, it's almost like a dance. Not sure how other drivers would describe it, so would be interesting to hear from Darwin, Roger, Marc, Chad here too.
    Shane Hill
    "If you are not capable of going through the gates, go play Shuffle Board."
  • MarcoMarco Posts: 912 Baller
    @ShaneH-Great explination. One of the tricks I use to not over correct is to drive with the palm of my hand controlling the wheel. I don't wrap my fingers all the way around. Thus, my countering and blocking are done more by pressure (pushing on the wheel) as opposed to turning the wheel. It helps make the movements much more subtle. What are your thouhts on this technique?
  • ToddLToddL Posts: 1,050 Crazy Baller
    One thing that hasn't been said, but I think it implied is: The pylon's path should ideally be straight and centered all the way down the boat guides. The "pointing" of the nose of the boat varies in order to ensure the pylon stays in a straight path. Think of looking down from directly above the pylon... the boat is slightly pivoting around the pylon (nose moves left, rear of the boat moves right, but the pylon stays centered). The subtle pivoting of the boat results in applying force not only forward down the course, but also slightly left or right to resist the skier's force to pull the boat's pylon off the ideal, centered path.

    Just as doing no corrections on the wheel will result in the pylon's path not being straight, also over correcting or reacting too much will cause the pylon's path to not be straight. Further, the timing of these subtle corrections is a factor of success. Anticipate too early and there is no skier load there to balance with resulting in the driver putting the pylon off center. React too late and the skier pulls the pylon off the center line and you have to correct more to recover the pylon to the center line.

    I've watched some end-course videos of skilled drivers and you can really see the pylon's path is damn near perfect. However, when you focus on the nose or rear of the boat, you see the dance as it works in balance with the skier's forces to keep that pylon headed straight down the lake.
    Todd Leach - has taught hundreds of beginners how to run their first pass.
  • SkiJaySkiJay Posts: 1,337 Mega Baller
    @ShaneH Skiers pull out at different times and intensities. In anticipation of the pullout, do you use some peripheral vision in the mirror to time it, or counter the pullout purely by feel and boat path?
  • ShaneHShaneH Posts: 4,901
    It's a feel thing based on their opener. You just have to be ready to counter their move out, back in and block through the gate. A 2 handed gate skier I'm ready to counter their gate move out when I'm approaching the 55s. A one handed gate skier when I'm passed the greens. The nice thing about the move out is that it's typically not abrupt so you can feel them as they start to roll the ski over.
    Shane Hill
    "If you are not capable of going through the gates, go play Shuffle Board."
  • SkiJaySkiJay Posts: 1,337 Mega Baller
    edited September 2012
    Thanks ShaneH. Thanks everyone. Excellent thread!
  • ShaneHShaneH Posts: 4,901
    You're welcome. The gate move out counter was something that Chad was telling another driver at a record after watching him in the end course camera. I made sure when it was my turn up to drive, that he couldn't say the same thing to me after watching it. LOL. A lot of this stuff are things you just don't pick up until someone tells you.
    Shane Hill
    "If you are not capable of going through the gates, go play Shuffle Board."
  • WaternutWaternut Posts: 870 Solid Baller
    I do think it's funny how there are course skiers and drivers and open water skiers and drivers. I've been driving boats and pulling skiers for over 15 years but I started pulling someone on the course this year. I felt like an absolute noob! I felt terrible for the guy I was pulling. I've gotten a little better as I watch others drive and get little tid bits of "best practices" but even with all of that, I feel bad if the guy falls on his first or second pass because he makes them most of the time and it makes me wonder if I did something wrong.
  • ShaneHShaneH Posts: 4,901
    @jfw432 It just takes time behind the wheel. And listening to what the skiers and other drivers tell you. Don't be afraid to say "Sorry, that was me." Or "is there something I could do better?".
    Shane Hill
    "If you are not capable of going through the gates, go play Shuffle Board."
  • DWDW Posts: 952 Baller
    @Brent: I think there are a couple of assumptions made that don't account for the complete story. You assume no boat slip in the water, and if there is side load, there will be side slip and also, if you assume no side motion relative to the water and if there is some in the direction of where the boat is pointed, then that translational velocity or distance travelled may/does add to the velocity of the skier relative to the water (adds if past the apex, reverse if not).
    Do you mean for angle alpha to be relative to the boat or relative to the boat's direction of travel, which will/can be different based on sideslip.
  • LeonLLeonL Posts: 544 Baller
    edited September 2012
    Great thread, @ShaneH makes a good point that I try to employ. I try to always ask skiers, especially the top guys I pull, how it felt and if they have comments or suggestions. I strive to continue to learn and get better. I'm a senior driver, but I don't think that I know it all. Some drivers seem to be resistant to suggestions, but that's life.
    Leon Leonard Stillwater Lake KY - SR Driver SR Judge
  • BrentBrent Posts: 3,583 Solid Baller
    @DW
    I made no assumptions , it was a e-mail from my friend Eric that I thought would make for a great thread & it has..

    I hear picking up the skier in reference to driving short line guys & yes there is a dance kinda quality to doing it correctly ,I can only go by skier feedback & have never driven in a tournament
    Just a BOS ex-con tryin to stay outta trouble.
  • ShaneHShaneH Posts: 4,901
    @LeonL One of the coolest things I've seen was a friend who's a Sr driver got to drive Chet Raley at a tournament. Since Chet was the last skier, my friend asked him for feedback at the dock. Chet had a 10 minute conversation with him about how he drove, how it effected Chet, and where it effected him. It wasn't adversarial at all. Chet was very gracious and made a lot of compliments and suggested some things too. All it took was asking. I think everyone standing around learned something from hearing the conversation.
    Shane Hill
    "If you are not capable of going through the gates, go play Shuffle Board."
  • GregDavisGregDavis Posts: 191 Baller
    Great thread, Love the comment, "it's like a dance," when you ( as the driver ) hoop up with the skier, well, it's a great feeling. Seat time, seat time, seat time, always be receptive to feed back. If possible get in the boat with one of the top driver in the country. Ask questions, give 100% of focus and attention to the skier, don't let passangers distract you. No Chit Chat in boat about where to have dinner etc. ( SR driver for 20 years) Best pull in tournament 2 at 41, best pull in practice 4 at 41. ) drove a couple tournaments the past several weeks, ( buckeye buoy tour in Ohio) Most fun I've had in a long time. (handicaped, head to head format,), Pulling kids, 16, 18, 20 MPH watching them improve every round, that's what it's all about, having fun.
  • jipster43jipster43 Posts: 1,083 Solid Baller
    Thanks everyone! I feel I have just enough information to go out tomorrow and really screw up someone's set!

    My biggest problem is being aware of the skier. I'm focused on the boat path and sometimes the skier is so light on the line that I'm not sure where they are in the turn and I can't see them. I suppose it just takes more experience.

    Has anyone ever gone to a driving clinic and did you find it worthwhile?
    JP Polsak - Otter Tail Lake, Bozeman, Montana
  • BrentBrent Posts: 3,583 Solid Baller
    edited September 2012
    @jipster43
    Can't you hear the skier ,I doubt meny of the top drivers see the skier as much as they can hear them in the turn & the zone for picking the skier up remains pretty much the same.
    Just a BOS ex-con tryin to stay outta trouble.
  • ShaneHShaneH Posts: 4,901
    edited September 2012
    I can't hear the skier over a 340hp+ v8 engine at 3500-4000 rpm. Heck, if it's a CC200 you can barely hear yourself think!

    @Jipster43 You just get a feel for it. Takes seat time and driving for a lot of skiers. Don't be afraid of screwing up. Might you? Sure. But get into the seat confident that you are going to learn something during each set you drive. Keep a driving log and write it down afterwards. Note who the skier is and what you felt with them or what you perceived. You can go back and look at those notes later.
    Shane Hill
    "If you are not capable of going through the gates, go play Shuffle Board."
  • 6balls6balls Posts: 2,510 Crazy Baller
    Great thread with great advice. Really drove mentally the other day for my bro. At times was very in synch and it was pretty cool.
    Dave Ross--die purple die
  • Chad_ScottChad_Scott Posts: 79 Open or 55K Rated Skier
    This is a great thread, I concur with the things Shane has said. I think to be a good driver you need to study your boat path even if its from just pulling practice. You will be surprised how humbling it is to put a camera at the end of the lake when you are pulling practice. I take my video after every tournament and watch my end course video. While at the Malibu Open I also spent a lot of time watching Chris Eller and Will Bush. I believe you also have to study the high end skiers that you are pulling. Every skier does not ski the same way, Dont be afraid to ask them afterwards what they feel, likes or dislikes. Each skier does not always want the same thing. For example, Chris Parrish wants a tighter line on the back side of the buoy than Nate Smith. He wants you to wait a little longer before you pick him up out of the buoy. It is important to drive and feel whats going on on the pylon, know where the skier is at all times. I think a good driver stays just a little ahead of the skier throughout the course. When you get behind the skier you will see the boat taking hits and the back of the boat moving towards the skier at the finish of the turn. When they are behind the boat moving from side to side, I want the boat to be a solid post as they lean against it. This will give the skier the arch they arelooking for. If i have the boat moving the same direction as the skier is going, then I am chasing the skier and we are headed in the same direction. When this occurs the skier and boat are going in the same direction and i am hindering the skiers ability to gain speed and maximize his or her width off the second wake. It is a dance between the driver and skier and when you both are in sync it makes the course feel narrow and slow. Driving is like skiing practice, practice practice and then watch what you are doing by utilizing end course video.
    klindyTexas6
  • Than_BoganThan_Bogan Posts: 3,153 Mega Baller
    edited September 2012
    Chad -- Great to hear your voice on this. Can't be much more authoritative than a multi-time WR puller!

    Can you say more about what it means to "pick up" a skier later or earlier (re Parrish vs. Smith comparison)? What exactly are you doing with the wheel and/or when/where are you pointing the boat in each case?

    Jamie is very much in the camp of wanting tension all the way around the ball, so I assume that's more like the Parrish scenario? At some point I may end up driving for Jamie, and even though it would be in a Class C, I'd like to give him the best chance of course!

    I've driven a few successful tournament -38s for people for whom that's a very good score, so I feel my driving is "decent." But I seriously doubt I know what I need to know to drive -41!!
    Dear 39 off: Please stop laughing at me. You are hurting my feelings.
  • Chad_ScottChad_Scott Posts: 79 Open or 55K Rated Skier
    Basically as Shane said i will counter steer or slightly point the nose of the boat to the opposite direction. For Parrish and Jaime, I will make this move a little quicker on the back side of the buoy than I would for Nate. And really this only comes from watching the skier and talking to the skier after driving them. Trust me skiers at 38, 39 and 41 off can tell you everything you do to the boat while they are on the line. They can feel everything, so ask them and let them know that you have thick skin and can take the criticism. If you stay a little ahead of the skier, then your boat path will be less effected and you will work in sync with what the skier is doing
    Than_BoganMattPSkiJayTexas6
  • Than_BoganThan_Bogan Posts: 3,153 Mega Baller
    Perfect -- thanks Chad. There aren't a lot of guys in N.E. who have the slightest hope at -39, much less -41, but hopefully I'll get a chance to drive somebody like that at some point and get some ideas from them.
    Dear 39 off: Please stop laughing at me. You are hurting my feelings.
  • elrelr Posts: 112 Baller
    Thanks Chad/Shane et al great advice . . .

    I have a semantics question bred out of very limited experience pulling very short line. When you say "I will counter steer or slightly point the nose of the boat in the opposite direction" does that mean that when the skier is at the backside of one ball you slightly point the nose of the boat at the 1, 3, 5 side of the course or the 2, 4, 6 side of the course?

    Thanks
    Ed
    Ed Rink - LSF Texas
  • Chad_ScottChad_Scott Posts: 79 Open or 55K Rated Skier
    When the skier is at the back side of one I am slightly pointing the nose of the boat towards two ball. This helps the skier maintain a tight line to complete the turn on out of the buoy
    Skoot1123
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