# Slow speed steering on a Sea-Doo PWC **URL:** \ **Category:** Factual Questions\ **Created:** [August 10, 2022, 8:53pm UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453 "2022-08-10T20:53:28Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [August 10, 2022, 8:53pm UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/1 "2022-08-10T20:53:28Z")
I own a Sea-Doo SPARK TRIXX 2 UP that I love to ride. It’s incredibly lightweight, has a 90 HP engine, and I can quickly get it up to 50 MPH on relatively flat water. I live in a house with a dock on a canal, off a private marina, and off a river that spills into a very large lake. The canal and marina are posted with no wake zone signs, so I must keep my speed down until I reach the river. At normal speeds, it has precise steering, but at low speeds, under five mph, it’s almost impossible to keep it going straight. It swerves back and forth from side to side. It’s as if I’m constantly over or understeering, but I’m not. There’s no way I can go three mph in anything approaching a straight line, which makes getting around boats and obstacles tricky. However, it steers perfectly straight with no effort if I take it up to five mph. But at five mph, I’ve got a wake. So what’s happening here? Do all PWC do this? Is it because it’s so lightweight? ---
**Author:** ![DorkVader](https://avatars.discourse-cdn.com/v4/letter/d/73ab20/32.png) [@DorkVader](https://boards.straightdope.com/u/DorkVader)\ **Post date:** [August 10, 2022, 9:07pm UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/2 "2022-08-10T21:07:43Z")
I ain’t a watercraft mechanic, but it sounds like maybe something mechanical is wrong, have you had it looked at? Like maybe a linkage is broke/loose/bent or something, or perhaps the impeller shaft has something wrong with it perhaps(it is jet propelled, yes?). ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [August 10, 2022, 10:04pm UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/3 "2022-08-10T22:04:53Z")
No, it doesn’t have a prop. The fact that it works perfectly above five mph makes me think it isn’t a mechanical issue. I guess I have to talk to someone who owns one to see if theirs does it too. ---
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [August 10, 2022, 10:06pm UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/4 "2022-08-10T22:06:57Z")
This sounds like normal PWC behavior to me. There’s no rudder, so it requires propulsion to steer. Less propulsion means less responsive steering ability. You’ll get used to it eventually, but it will always perform better when its just a little bit faster. ---
**Author:** ![Tride](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tride/32/13907_2.png) [@Tride](https://boards.straightdope.com/u/Tride)\ **Post date:** [August 10, 2022, 10:08pm UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/5 "2022-08-10T22:08:10Z")
Has it done it since new? Could the impeller nozzle be loose? I have limited experience with PWCs, but they throw very little wake at high speeds 😆. They don’t have much of a keel, so maybe it’s just squirrely? ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [August 10, 2022, 10:12pm UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/6 "2022-08-10T22:12:13Z")
> [@Tride](#): > > They don’t have much of a keel, so maybe it’s just squirrely? That occurred to me, and at high speed, they are up on the water, so maybe that’s why they are so squirrely at low speed. I just thought someone much more intelligent than me could say they all do that. ---
**Author:** ![DavidNRockies](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidnrockies/32/6279_2.png) [@DavidNRockies](https://boards.straightdope.com/u/DavidNRockies)\ **Post date:** [August 10, 2022, 10:13pm UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/7 "2022-08-10T22:13:43Z")
Ever try pedaling a bicycle _really, really_ slowly ? My guess is it’s the same kind of instability. ETA: interesting find: > **[Controlling Low-Speed Wander | Boating Mag](https://www.boatingmag.com/how-to/controlling-low-speed-wander/)** > > Causes and possible cures for low-speed wander. > [@](#): > > Roy Ellis, senior project manager of product development for Monterey Boats, said it’s the result of water rushing aft along the sides of the boat and then collapsing into the hole behind it. > > This creates swirling vortices of water that exert suction on each side of the transom, pulling the boat back to the right and then left, Ellis said. This article isn’t specific to PWCs, but the theory seems right. ---
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [August 10, 2022, 10:16pm UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/8 "2022-08-10T22:16:44Z")
> [@dolphinboy](#): > > I just thought someone much more intelligent than me could say they all do that. While we wait for that more intelligent person to come along, I can say that, In my experience, they’re all pretty much like that. ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [August 10, 2022, 10:21pm UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/9 "2022-08-10T22:21:28Z")
I’ve never used one, but it’s my understanding that these things don’t have a rudder, in the normal sense. All they have is a steerable jet outlet. It only steers by pushing water away from the direction you want the back of the thing to go. In that, it’s similar to a rudder, except that it quits working when you aren’t using the throttle. I’ve heard this causes PWC renters to have accidents, because the handlebars don’t work at all without throttle. (While I was writing that, other people already posted most of that.) Perhaps the answer is to steer at low speeds by short directional blips of the throttle instead of a steady low throttle. It is a boat, after all, so it will keep moving in between steering surges. ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [August 10, 2022, 10:22pm UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/10 "2022-08-10T22:22:43Z")
Thanks, AskNott. It’s worth a try. ---
**Author:** ![Tride](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tride/32/13907_2.png) [@Tride](https://boards.straightdope.com/u/Tride)\ **Post date:** [August 10, 2022, 10:27pm UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/11 "2022-08-10T22:27:23Z")
Are you on Flathead lake? I’ll come troubleshoot! ---
**Author:** ![Princhester](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Princhester](https://boards.straightdope.com/u/Princhester)\ **Post date:** [August 11, 2022, 12:31am UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/12 "2022-08-11T00:31:18Z")
It’s normal behaviour. There is little about a PWC hull to give directional stability - no rudder, little or no keel, not much by way of strakes. Add to that - the jet is powerful and even tiny directional inputs at low speed easily overcomes any directional stability the hull may have. As the speed rises, the hull’s (modest) directional stability becomes more effective, and the PWC becomes more steerable. ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [August 11, 2022, 1:20am UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/13 "2022-08-11T01:20:51Z")
> [@Tride](#): > > Are you on Flathead lake? I’ll come troubleshoot! Yes… you’re welcome to come. ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [August 11, 2022, 1:25am UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/14 "2022-08-11T01:25:03Z")
> [@Princhester](#): > > It’s normal behaviour. There is little about a PWC hull to give directional stability - no rudder, little or no keel, not much by way of strakes. Add to that - the jet is powerful and even tiny directional inputs at low speed easily overcomes any directional stability the hull may have. Okay, I can see that, but if the jet is pushing straight backward at idle speed (three mph), and the steering is pointing straight forward, what force is pushing it strongly to one side or the other? IOW, what makes it wander left or right if I am steering forward? Remember, at 50 mph it goes straight forward if I am pointing that way. Steve ---
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [August 11, 2022, 2:17am UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/15 "2022-08-11T02:17:55Z")
> [@dolphinboy](#): > > what force is pushing it strongly to one side or the other? Wind, waves, current, torque, body lean and weight shift; same as when you’re going fast but you no longer have as much forward inertia, throttle or steering control that you have at higher speeds. ---
**Author:** ![Princhester](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Princhester](https://boards.straightdope.com/u/Princhester)\ **Post date:** [August 11, 2022, 2:21am UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/16 "2022-08-11T02:21:44Z")
One could as easily say “If I lift an object with one finger, why does it topple?”. The system has barely any stability at all, and you have forces acting on it. Going straight would be _an anomaly_. ---
**Author:** ![jnglmassiv](https://avatars.discourse-cdn.com/v4/letter/j/f07891/32.png) [@jnglmassiv](https://boards.straightdope.com/u/jnglmassiv)\ **Post date:** [August 11, 2022, 2:36am UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/17 "2022-08-11T02:36:45Z")
> [@Bear\_Nenno](#): > > body lean I think this is going to be OP’s biggest influence. In small watercraft, little movements count. ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [August 11, 2022, 3:09am UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/18 "2022-08-11T03:09:18Z")
Okay. I’ll test it out tomorrow. For the record, at this time of year, there are no currents, waves, wakes, or wind to deal with in the canal. I will sit as still and squarely as possible and just point it forward at idle speed and see what happens. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [August 11, 2022, 12:26pm UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/19 "2022-08-11T12:26:58Z")
> [@DavidNRockies](#): > > Ever try pedaling a bicycle _really, really_ slowly ? > > My guess is it’s the same kind of instability. > > ETA: interesting find: > > [Controlling Low-Speed Wander | Boating Mag](https://www.boatingmag.com/how-to/controlling-low-speed-wander/) > > > [@](#): > > > > Roy Ellis, senior project manager of product development for Monterey Boats, said it’s the result of water rushing aft along the sides of the boat and then collapsing into the hole behind it. > > > > This creates swirling vortices of water that exert suction on each side of the transom, pulling the boat back to the right and then left, Ellis said. > > This article isn’t specific to PWCs, but the theory seems right. This phenomenon is called > **[Vortex shedding](https://en.wikipedia.org/wiki/Vortex_shedding)** > > In fluid dynamics, vortex shedding is an oscillating flow that takes place when a fluid such as air or water flows past a bluff (as opposed to streamlined) body at certain velocities, depending on the size and shape of the body. In this flow, vortices are created at the back of the body and detach periodically from either side of the body forming a Kármán vortex street. The fluid flow past the object creates alternating low-pressure vortices on the downstream side of the object. The object will t... ---
**Author:** ![DavidNRockies](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidnrockies/32/6279_2.png) [@DavidNRockies](https://boards.straightdope.com/u/DavidNRockies)\ **Post date:** [August 11, 2022, 1:21pm UTC](https://boards.straightdope.com/t/slow-speed-steering-on-a-sea-doo-pwc/969453/20 "2022-08-11T13:21:42Z")
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