Lateral Thrusters High Speed Video Completely Out Of Water

[JetBoatPilot]

Watch this video to see how the Lateral Thrusters get completely out of the water at high speeds. This means no loss in top end speed and no additional loads and forces on the part which would shorten life span and increase risk of submerged object impact.

 

[Scottintexas]

Love the videos ! Great view point

 

[KyleWade14]

Wow that is pretty awesome. I would have thought the jet would be more underwater.

 

[fraserjr]

@JetBoatPilot appreciate all of the great videos on the Lateral Thrusters. One thing that would help me would be a "steering/directional" diagram for different situations for a twin engine boat. For example:

Move the boat laterally to the right - Example setting: Wheel hard right, starboard engine forward detent, port engine netural
Move boat back and to the left - Example setting: Wheel straight, starboard engine neutral, port ending reverse detent

I think that would really help me visualize how I can move the boat as compared to what I can do today without Lateral Thrusters.

 

[1WetBoat]

I think unintentionally this video also shows where the underwater LED's would be at while underway along with transducers. I know a lot of the LED's require them to be submerged to prevent overheating.
Great video Will.

 

[Bluewater272]

I think unintentionally this video also shows where the underwater LED's would be at while underway along with transducers. I know a lot of the LED's require them to be submerged to prevent overheating.
Great video Will.

Helping me with transducer placement, too!

 

[ruztew]

My mind is blown, I assumed the jets were under the water when underway....

 

[Sbrown]

A lot of people think that thrust is generated by the jet of water pushing against the water around it when actually thrust is generated by a pressure differential inside the pump. Which is also why some of the claims I've seen made about certain add-on equipment make absolutely no sense from a physics standpoint.

 

[2kwik4u]

My mind is blown, I assumed the jets were under the water when underway....

I bet most people do. They can be underwater, but don't have to be.

Jets (anything with a nozzle really) don't work by "pushing" on the water behind you (as Jet aircraft don't "push" on the air either. They instead trade momentum for movement.

Do this thought exercise in your head. Stand in a small john boat holding a really heavy object (lets say a 36in tube TV). Now, throw that object out the back of the boat. What happens? The boat moves forward based on the interaction between the relatively high momentum of the TV, and the relatively low force required to move the boat forward. NOW.......do the same thing with a very very high number of very light things (water droplets in our case of a jet boat). Same results.

The jets are essentially throwing high amounts of momentum out of the back of the boat in exchange for the force to move the boat forward.

I'll try to dig up my notes from Fluid Dynamics when I get home and post the equations that make this work. It was completely fascinating to me when I learned the first time!

A lot of people think that thrust is generated by the jet of water pushing against the water around it, when actually, thrust is generated by a pressure differential inside the pump. Which is also why some of the claims I've seen made about certain add-on equipment make absolutely no sense from a physics standpoint.

You beat me to it

 

[Renod]

I'll try to dig up my notes from Fluid Dynamics when I get home and post the equations that make this work. It was completely fascinating to me when I learned the first time!

Very cool. Just please remember to use small, simple words for some of us!

 

[Cobra Jet Steering LLC]

The basics as we all should understand, prop boats pull thus the name screw for the prop.
However jet propelled boats push , now air is compressible but water is not thus comparing a airplane to a boat totally different animals and to take it one step further the lateral thrust device takes away some of the reverse thrust exiting the bottom of the nozzle and redirects it to one side or the other to change the direction of the back of the boat so your own statement claims incorrectly that this won't work !
Just like my mega fangs capture more of the very same reverse thrust exiting the nozzle from the very same place the side thrusters take their thrust from , but rather than bleed off some of that reverse thrust I focus it capturing more of it as useable directed thrust for stopping and for real reverse steering.
Same thrust just using it differently .
Now lets look at a sea doo reverse bucket that captures the thrust from the nozzle and redirects it in a way so that the boat turns in reverse completely opposite from a Yamaha boat. So it all works from the jet thrust being redirected in numerous different ways to create different results. . And undisputedly I might add. So Not rocket science actually

 

[Bluewater272]

Ugh.

 

[scokill]

I've been gone awhile but seems like a lot posts on the latest dohickeys.

 

[AZ Native]

Seeing this video may be the coolest revelation I've experienced since buying my first jet boat 2 years ago. Obviously I never stuck my head under the back of the boat at full speed to see what happens, but wow, I never expected that. I know Will had a different objective in mind while filming this, but the general educational value caught my interest. I had no idea how this worked, I'm a consumer who usually only cares that it does work. I'm going too assume however, that low speed maneuvering uses completely different principles since the jets are underwater and they must act like a hose nozzle turned up full blast in a pool pushing the hose around. In that case we really are pushing the boat?
Now my really stupid question. If the jets are completely out of the water, what the hell makes the boat turn if they're not pushing the boat??
BTW my new term to impress my grown kids is "Fluid Dynamics". It just sort of roles off the tongue. I hope they don't ask me what it means.

 

[Cobra Jet Steering LLC]

 

[swatski]

So - FWIW - here is one of my favorite jet boat pics - that (I think) @Williamsone46 posted some time ago - showing a 2015+ 240/242 hull/stern/jets at planning speeds:

Pretty cool!

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[Peelz]

awesome product aside, what a sweet viewpoint.

 

[Sbrown]

Seeing this video may be the coolest revelation I've experienced since buying my first jet boat 2 years ago. Obviously I never stuck my head under the back of the boat at full speed to see what happens, but wow, I never expected that. I know Will had a different objective in mind while filming this, but the general educational value caught my interest. I had no idea how this worked, I'm a consumer who usually only cares that it does work. I'm going too assume however, that low speed maneuvering uses completely different principles since the jets are underwater and they must act like a hose nozzle turned up full blast in a pool pushing the hose around. In that case we really are pushing the boat?
Now my really stupid question. If the jets are completely out of the water, what the hell makes the boat turn if they're not pushing the boat??
BTW my new term to impress my grown kids is "Fluid Dynamics". It just sort of roles off the tongue. I hope they don't ask me what it means.

Honestly, I've held back responding to this thread because I'm trying to avoid arguments. But I can't not answer your question either. In the simplest terms, all of the force that makes your boat move happens inside the pump. The reason it turns when you change the angle of the nozzles is due to something called "thrust vectoring" which simply means that when you change the angle of the center of the low pressure area (the water escaping the high pressure of the pump), the center of the high pressure area (inside the pump opposite the nozzle) changes as well. And for the record, boat propellers, airplane propellers, helicopter rotors, aircraft wings and our jet pumps, all work on the same physics principles and to a certain extent, yes, it actually is rocket science. It really works off of two simple principles. 1: Any gas or liquid will flow from a high pressure area to a low pressure area. 2: All actions have an equal and opposite reaction. As an answer to your last question, yes the pumps are pushing the boat, just the jet of water is not pushing the boat directly. You could put your boat 20 feet in the air, and if you feed your jets water, the boat will move forward, turn, etc. Hell, you could put the boat in a vacuum and it would still work if you fed the jets water.

 

[swatski]

Honestly, I've held back responding to this thread because I'm trying to avoid arguments. But I can't not answer your question either. In the simplest terms, all of the force that makes your boat move happens inside the pump. The reason it turns when you change the angle of the nozzles is due to something called "thrust vectoring" which simply means that when you change the angle of the center of the low pressure area (the water escaping the high pressure of the pump), the center of the high pressure area (inside the pump opposite the nozzle) changes as well. And for the record, boat propellers, airplane propellers, helicopter rotors, aircraft wings and our jet pumps, all work on the same physics principles and to a certain extent, yes, it actually is rocket science. It really works off of two simple principles. 1: Any gas or liquid will flow from a high pressure area to a low pressure area. 2: All actions have an equal and opposite reaction. As an answer to your last question, yes the pumps are pushing the boat, just the jet of water is not pushing the boat directly. You could put your boat 20 feet in the air, and if you feed your jets water, the boat will move forward, turn, etc. Hell, you could put the boat in a vacuum and it would still work if you fed the jets water.

Yep. It's all good ol' Bernoulli's effect.
Just like strong wind lifting roof off building.

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[adrianp89]

Honestly, I've held back responding to this thread because I'm trying to avoid arguments. But I can't not answer your question either. In the simplest terms, all of the force that makes your boat move happens inside the pump. The reason it turns when you change the angle of the nozzles is due to something called "thrust vectoring" which simply means that when you change the angle of the center of the low pressure area (the water escaping the high pressure of the pump), the center of the high pressure area (inside the pump opposite the nozzle) changes as well. And for the record, boat propellers, airplane propellers, helicopter rotors, aircraft wings and our jet pumps, all work on the same physics principles and to a certain extent, yes, it actually is rocket science. It really works off of two simple principles. 1: Any gas or liquid will flow from a high pressure area to a low pressure area. 2: All actions have an equal and opposite reaction. As an answer to your last question, yes the pumps are pushing the boat, just the jet of water is not pushing the boat directly. You could put your boat 20 feet in the air, and if you feed your jets water, the boat will move forward, turn, etc. Hell, you could put the boat in a vacuum and it would still work if you fed the jets water.

So you're telling me if I can recycle the water from the jets back into the jets... and add wings.. I can fly with my boat? @swatski is this on your mod list yet?