Any thoughts of an artifical speed bar built out of sand bags or old tyres. Has it been discussed about the options
Bjorn Dunkerbeck was working on a chop reduction system. I think it's a line of floating buoys. It could be a little easier than building a bank. Maybe all of us could chip in at our local spot?http://www.boardseekermag.com/special_features/bjorn_interview/bjorn_dunkerbeck_interview.htm
Could benifit everyone who wants to go fast. surely if we all have a good think about it we may come up with some good ideas,or improve the ideas that already exist. Yes I am looking at crab country.shallow an easy access. out of the way of boaters.5000 sandbags for an 850m wall. That is a guess
Bjorns first system is on his website www.dunkerbeck.com/ - go to the projects/world speed sailing link for a vid of Bjorn, Antoine, Robby and Anders.
For the mandurah mile we just need someone to donate an old excavator to dig and pile our own sandbar custom shaped and angled for the speed run and maybe to do away with those limestone outcrops in the middle of the strip as well
The common detail for foreshore restoration around here is big sandbags made of geotextile cloth with some kind of "rubber" coating. They look pretty cheap and colourful.
What about linking some big foam blocks together ...say 8x4x2 feet..anchor at both ends..one portable and realatively cheep speed run...storage may be a problem but if everyone took one home.....The more poeple that turn up on the day the longer the run
What about opening a can of HTFU
Kinda ironic after I crapped my pants last weekend with the conditions
It apears that you can rework the coast if you are a property developer or a mining company but if you are joe average and thought of doing something to return Woodies or the Pt Walter sand bar to their original shape I'm sure you would be prosecuted for environmental damage.
Perhaps you could borrow a dredge and extend the islands in the estuary.
www.google.com.au:443/maps?f=q&hl=en&geocode&q=yunderup+&sll=-25.335448,135.745076&sspn=70.989864,108.28125&ie=UTF8&ll=-32.593531,115.752747&spn=0.004266,0.010772&t=h&z=17
It looks like they were formed from dredging a channel in the first place.
I've given this some thought as well.
What about a big long plastic tube, half filled with water (the other half filled with air), anchored at points along its length.
The water would give it mass, the air would keep it floating, and you could just open one end and roll it up from the other for storage. I'm sure that someone in industry can source some sheet tube...
Only problem I can see is that the air might all run to one end so parts of the tube might bow upwards... maybe more anchoring points might be needed.
Following on from YoYo, the major hurdle will be getting approval for such a thing.
Given Peel Inlet is the ideal location and it's big enough and shallow enough, we have to start building relationships with the relevant authorities.
There was talk of starting up a Mandurah Windsurfing Club (MWC), and Council reps said that council would provide and invest in facilities for clubs, maybe we need to seriously think of becoming a club??
Re MWC: Local discussions have come up with 2 major issues, lack of motivation which can be easily overcome, but the 2nd point of the inevitable power struggles that happen in clubs, which could ruin some great friendships that have grown out of the informality of windsurfing in Mandurah, and this I would be seriously concerned about, and what stopped me moving with it (I have all the relevant paperwork).
A light tube half filled with air will NOT achieve a good result. All it will do is allow the waves to pass under. You need to have something with a different mass and resonant frequency to the water (which is the only reason water will not work).
Waves are energy
Energy must be absorbed, it cannot be destroyed. (Energy absorbtion is the only way of flattening waves)
in a perfect world you would have a floating mass with resonant frequency 180 degrees out oif frequency to the waves. This is almost impossible because real ocean wave fields are not composed of single frequency waves.
So the next best solution is to have an floating object with a lot of damping. For this you need a floating device with large horizontal planar area (Hence the flat sheets that Bjorn uses in the picture above.
The downside of Bjorns setup is that because the floating signs have relatively little mass, they cannot absorb much energy, allowing a lot of wave to pass through the device (you can see some reasonably big waves on the leeward side of the device. If the device had large horizontal steel planes about 50cm below the surface it would be MUCH more effective. Then you only need to mange the issue of storage, transportation, deployment, cost etc. :-(
Not alot of help I know, but I thought it best to raise this issue before anyone spent any money on this proposition.
Take a look at some Wave Energy Devices, in particular Salters Duck (great conspiracy story too) for the high performance industrial stuff. Or try to emulate a swimming pool lane rope system, where the lightweight floating body translates the vertical wave motion into damped axial turning moment.
JB
Hmmm. You might be right there JayBee.
I was thinking that the waves would sort of crash against the air bit and dissipate somehow... hadn't quite thought of where the energy would go, however.
Might have to do some experiments methinks.
Nebbs i reckon your idea would work in a shallow location like melville or hardies where the chop doesn't have the distance to build.
What about lenghts of 400mm pipe, sealed (or filled with foam)so they float and linked together. It could be anchored off one end so it would pivot with the wind.
You could have anchor points all along the length.
I am hoping that the round edge of the pipe will help in dissipating the chop and energy.
Hi JayBee
I hope you're not flogging "The floating pipeline across botany bay to the desal plant as being good for windsurfing" again are you?
Jethrow
Jethrow, some day the full extent of my genius will be recognised. The pipe on botany bay is a great idea - except they are going to sink it, not float it. Of course we could just dam the mouth of the bay and pump out water until the pipeline is exposed ???????????
In a previous life I made a poor career move and was on the research and design team for a wavepower device (Oscillating Water Column) on the island of Pico (Azores). Some day when there is no wind I will regale the formula fleet with the tales of misfortune, woe, corruption and many nutbag proposols.
JB
secondhand shipping containers you can pick them up for around 2-3k they would stop any waves
What has really worked for us is NSW and Vic irrigators sucking the life out of the murray. It has created some great speed spots by exposing banks everywhere. To make things better all the pesky trees that block the winds are dying so we are getting nice clean air. In a couple of months the fish induced high speed crashes will be a thing of the past and the extra salinity is helping to plane sooner.
Whisper wave claim 90% of wave energy is absorbed by the device, ie a 30 inch swell turns into a 3 inch swell.
I do remember a 30 inch swell out the back last weekend, and would have much preferred that it be 3 inches 
I wonder if they would hire 750 metres of the stuff out for an event?
Whiperwave looks pretty good,I wonder whether it could be modified so it did not rise so high above the water - because i think it would stir up wind turbulence.
They have a smaller verion for swimming BUT one place which uses the large version sinks it to 6 feet under the ice in winter so I guess it is adjustable depending on the water inside... it just the cost...
but this would be better. Concrete floating dock in 55knot winds.
http://www.shoremaster.com/images/video/clips/encoded/01_waves-512.wmv
Those wave attenuators look pretty good. Its a pity they don't harness the energy and generate power. Then someone would pay to install it for you.
There you go Nebbs, something to work on - a low profile linear modular portable wave energy electrical generating device. ooooh....
Good idea notwal, but how about running lights on it with the energy generated, then it's a 24/7 proposition!
