Surf wave brainstorm

[Jetlink]

Not hydro dynamics but it's a very similar principle as aerodynamics of which I know enough to be dangerous. But as said before, to compensate for a slower speed, you either need to increase the angle of attack or the shape of the wedge.

[86 century]

My thoughts on the idea are to make the angle of attack adjustable to compensate for lower speed(less flow).


Can you give us(me)some examples of the more efficient wing shapes.

All I have to start with as far as shape and size is the malibu wedge. The hulls are quite different so I don't know how well it will work.

[CornRickey]

I maybe mistaken but the wedges are designed for higher speeds like wakeboarding. Is the pitch adjustable? I'm assuming you can not put it down all the way but this would turn it into more of a drag brake than a downward force concept. I'm thinking (using my aircraft knowledge also) the whole wing would need to be redesigned with a greater surface area and greater pitch to compensate for the slow speed of wakesurfing.

[Jetlink]

Well, you could increase the angle of attack like I said thereby making the wedge/wing take a bigger bite of the water and exert a greater downward pressure, you could also change the camber without changing the angle of attack to compensate for a slower speed requiring more downforce. Check out this link and play around a little and see what I am talking about. If you have any questions after that, I will do my best to answer them.

http://www.grc.nasa.gov/WWW/k-12/airplane/foil3.html

Just quickly playing around with it, I was able to find a foil that exerts almost 4600 pounds of downward pressure while only creating 950 pounds of drag to overcome.

[86 century]

Thanks for the link I will play around to see what I can come up with.

I wonder if wood or fiberglass laminated over steel would hold to test different upper and lower camber profiles as having them machined will get rather pricey

[NorCalPR]

The surf gate isn't like a wedge where it's pushing the boat up or down. I'm sure there's some slight upward pressure on the non surf side but that's not the main idea behind the surfgate.

What the surfgate dows is change the convergance of the wake (where the wake from the left side and the right side of the boat come together). By extending the paddle on the opposing side of surfing, you're essentially making the convergance on the non-surfing side further back. What that does is make the surf wave on the surfing side.

You still have to load the boat. You still need weight front and rear. It also seems like people are slightly loading the surfing side more still, but not like now where you have to have 500-1000 lbs more on one side to get the boat to lean. Maybe only 100-200 lbs more on one side of the boat more.

It also seems like there's not a whole lot of pressure added onto the teak. There's a couple guys that bootyfabbed a setup over on the Malibu forum, where they have have the paddle clamped to the teak. One Mastercraft guy reported maybe 80-100kg of force on the paddle itself. Makes sense since 5psi = 20mph, 11 psi = 30mph, 19 psi = 40mph, 30 psi = 50mph (Taken from a Airguide Speedometer writeup). So We'll say that the PSI at 10mph is 3psi. A paddle that is 10X20 at a 45 degree angle will roughly have 100square inches of surface area, equaling 300lbs of force. They're not at a 45 degree angle, more like 20 degrees, so the force is probably somewhere around 150lbs. The teak and transom is more than capable of holding this

The only negative thing I have seen so far is that the paddle will make the boat want to track wierd when moving slow to pickup a rider. The new Malibu's do not have this problem because they automatically pull in at about 7 mph.

This may be my project for the summer. We surf behind the Comp a lot, and it's leaned over a lot. The problem is when we have goofy/regular footed riders, and it takes half an hour to switch everything over. With this setup, even if it wasn't hard mounted to the boat (making a couple paddles that quick connect/quick disconnect on the lake) the change over time would be dramatically reduced.

[2500HD]

The surf gate isn't like a wedge where it's pushing the boat up or down. I'm sure there's some slight upward pressure on the non surf side but that's not the main idea behind the surfgate.

What the surfgate dows is change the convergance of the wake (where the wake from the left side and the right side of the boat come together). By extending the paddle on the opposing side of surfing, you're essentially making the convergance on the non-surfing side further back. What that does is make the surf wave on the surfing side.

You still have to load the boat. You still need weight front and rear. It also seems like people are slightly loading the surfing side more still, but not like now where you have to have 500-1000 lbs more on one side to get the boat to lean. Maybe only 100-200 lbs more on one side of the boat more.

It also seems like there's not a whole lot of pressure added onto the teak. There's a couple guys that bootyfabbed a setup over on the Malibu forum, where they have have the paddle clamped to the teak. One Mastercraft guy reported maybe 80-100kg of force on the paddle itself. Makes sense since 5psi = 20mph, 11 psi = 30mph, 19 psi = 40mph, 30 psi = 50mph (Taken from a Airguide Speedometer writeup). So We'll say that the PSI at 10mph is 3psi. A paddle that is 10X20 at a 45 degree angle will roughly have 100square inches of surface area, equaling 300lbs of force. They're not at a 45 degree angle, more like 20 degrees, so the force is probably somewhere around 150lbs. The teak and transom is more than capable of holding this

The only negative thing I have seen so far is that the paddle will make the boat want to track wierd when moving slow to pickup a rider. The new Malibu's do not have this problem because they automatically pull in at about 7 mph.

This may be my project for the summer. We surf behind the Comp a lot, and it's leaned over a lot. The problem is when we have goofy/regular footed riders, and it takes half an hour to switch everything over. With this setup, even if it wasn't hard mounted to the boat (making a couple paddles that quick connect/quick disconnect on the lake) the change over time would be dramatically reduced.

you,ve done your research. i'll be making a quick release gate for my saltare in the spring along with a larger teak swimdeck.

[matt k]

I haven't seen one in person yet, but from the pics it just looks like a slightly big trim tab mounted sideways. Seems like that'd be a pretty easy thing to try, if you really wanted to.

[michael hunter]

Nautique came out with the NSS last year it works similar but mounts to the transom . It looks much cleaner and wont affect the turning ability of the boat. Here is some info about it.




The Nautique Surf System with WAVEPLATE was designed to create the ultimate surf wave with ease. Gone are the days of offloading ballast and people from side to side. Leave the ballast filled after wakeboarding and with the touch of a button through the Nautique LINC System, you will be surfing your wave of choice in no time. The WAVEPLATE is an integrated design that when deployed extends outward and down from the transom intercepting and redirecting the flow of water to clean up the opposite wake and form a surf wave like no other boat.


Nautique214 by nautiquehunter, on Flickr

[Jdm89supra]

I have seen the Malibu surf gate if someone wanted to make one its not hard I have thought about it but the older model boats like I have I just don't know if it will handle it. it could be done with a large trim tab on both sides and a 12in by 12in by 3/4in thick piece of lexan or plexy bounted to the trim tab its not a bad Idea at all