I bought the new Mistral Screamer 128 and its got a device called Hydroblade on the bottom near the nose. Apparently its to keep the nose down at speed like a spoiler.

Has anyone used one before and whats the effectiveness of it? Looks to me like could be a waste of time, but havent used it yet so will find out tomorrow.

PS Image at following link www.seabreeze.com.au/gallery/gallery.asp?imageid=2171

cool,
does that mean the hydro blade will be on display at the meet?

cheers
gestalt.

Probably not unless the wind picks up. Being a bigger guy (120kg) I wont be getting the new board out unless its 20+knts. Trying to loose some kg's so I can make better use of the board thou.

Looks a bit gimmicky, if it was serious enough to be effective I can see some really sweet catapults happening if it contacts the water. or hydro-blade... is it supposed to be in contact with the water, surely not up that far???

I agree with the gimiick comment. It should generate low pressure at the at the front of the board and suck it onto the water. The problem is your wetted surface is increase and therefor drag. Probably feel different to ride but it will probably slow you down. Then again if you are like me and not an expert rider you will probably feel nothing.

I agree TimB, Ill let you know thou after I have tried it, but I suspect its only going to benifit the experts (Which I am NOT)
That said, I have a Mistral Explosion 161lt and 80cm wide, not that much diff to this new board and in big winds and a bit of chop, I have often needed to keep the nose down. Maybe this is my answer?

mk, from what Simon said its air flow, not water flow. As I assumed when he was telling me about it. Its very close to the tip of the board. But I bet you would be right, if it contacted the water, expect some sudden jolts maybe?

PS The photo doesnt show it, but as you would expect there is a gap between the board and the 'blade'. But its only about 5mm.

Ok hobie, i'll talk to simon some time soon about it. Coming from cars I dont really see how we are going fast enough for the spoiler to pull the nose down. On a positive side it should make riding the nose a little easier.

I wouldnt picture it as a jolt really but definate decelleration as it grabs the water, shouldnt throw you over the front but if you are unbalanced for whatever reason you're history. Being a big guy though you shouldnt have much problem.

I cant tell if its for wind or water. The video says that it helps to get you ON the plane when in sub planning conditions, therefore I have to assume it does work based on water flow rather then air flow.

Looks like in this case it is for water rather than wind, but as a side issue in reply to mkseven about the effectiveness of a wind foil to keep the nose down, don't dismiss it.

I use a waterski helmet from Pointless instead of a Gath which I found didn't whistle, squeeze the face, make wearing sunnies a pain, or give me a hemmed in feeling. However it does make me look like a dick, especially since I took to wearing it Layton style as the peak kept the winter rain from running down the neck. On the last trip to Sandy the sun was out so to get a bit of protection I turned the sucker around. Halfway down the very next run the wind got under the peak and nearly ripped my head off. I was amazed at how much force there was.

I know Mal Wright has experimented with weights on the nose of his missile to get the trim he was after, I don't think a nose foil in the future is out of the question.

Re. the 5mm gap you mentioned - is that gap consistant right through - meaning that the water can flow between the 'hydrofoil' and the board undersrface. If this be the case - and the hydrofoil is a classic airfoil/hydrofoil/wing shaped cross-section. If the flat section of the foil is that closest to the undersurface of the board, then it would work like a mini wing of an aircraft only in reverse - the flat side is the low pressure side - the curved section being the high pressure - providing lift whether in air or water - only in this case - if I am correct in saying the foil is 'upside-down', then it will provide lift in a downward direction - and in this case serve to hold the nose down to some degree at speed.

Got the pressure thing backwards - should read high pressure under foil - but you know what Im on about!!

I am not dismissing it's value on a board, particularly a speed board which is running over 40knots, most good car spoilers start getting positive (measureable) downforce at 80km/h.

My issue with it is that it is on a reasonably narrow freeride board not intended to do superfast speeds.

I did indeed check out hobie's board today and it is an interesting concept, given that it is held in by screws he can try it out. It is not actually an aerofoil shape, it is aerofoil top section on the water side but the board side is concave shape. It is quite solid being made of carbon. The board itself has a quite purposeful concave to bring the air into the foil.

It is definately interesting and now that i've seen it I might make one or even grabe hobie's for a bit and try it in a slalom board I have that rides very nose high.

dont forget to watch the video in which Mark Nelson actually says that the 'HydroBlade' is designed to get the board 'onto' the plane. Thus when in sub planning condtions the blade is submerged and as the water flows between the blade and board it creates lift, pushing the board up and hence onto the plane. After watching that video I now think it has nothing what soever to do with pulling the nose of the board down at speed.

http://www.boardseekermag.com/moves_and_movies/MOVIES/IL_021_Mistral_Hydroblade512K_Stream.wmv

Unfortunately I cant watch movies on my computer at the moment but I will watch it after I get it fixed. I can see how it would tend to push the nose of the board up in the water.

Have seen the hydroblade and it is DEFINATELY an aerofoil section, but like a concaved aeroplane wing (Wright Bros. era) which is a low speed/high lift foil section, and running upside down. Will be interesting to have Hobie sail the board wing-on, then wing-off to see if the rider or GPS can tell the difference. We wait for wind for you Hobie!

Well I took the new board out yesterday with the Hydroblade attached....

It sailed like a dream Considering my existing board is a 161ltr and I am around 122kgs, I found that the Screamer 128ltr got on the plane immediately in 15-18knts where as in the same conditions on my 161ltr I would normally be struggling to get on the plane.

The foil is definately submerged in sub planning condtions, so as you move forward lift is grenerated on the foil. I believe it works, and works very well too!!

To me its like a difuser on a sports car, breaking up wind ( or in this case water)

Good to see it works hobie14t!

to be honest, I dont know how it actually works the more I think about it, its got me confused if you look at the shape of the 'blade'

All I know is that I was planning heaps earlier the I would have been on my 161lt board. I fully recommend giving it a try!

Remember the nostrils on the F2 missile II?

Never underestimate the power of a placebo.

The airpipes do work, the F2's have the cleanest wake i've seen. It's probably a bit hard to see on the missiles but on the SX's it is definately noticeable.

Hobie dont immediately put it down to the hydroblade though, smaller boards have many things which assist early planing- weight, less drag etc etc it might have just been that you're 161 was a bit of a barge.

anyone know if it would be possible to fit it to a different brand board other than the Mistrals it is designed and optioned for? I'd sure as hell like to plane earlier in marginal winds...

I reckon if your board has a concave near where it attaches on the Mistral boards then yeah, it would be possible I guess. Only prob would be installing sealed screw holes?

With out the concave to sit across, it would be almost no point as there would be next to no gap between the hydroblade and the board surface.

What do you think MK? I think you hinted at possibly trying something like this yourself?

I dont think you'd need the concave that much, more finding the right section of rocker to put it on. To install one you'd really need to insert some footstrap plugs into hull. The concave would definately help get airflow across the foil though- it would work well with centre channel boards also.

And pass I think I'll try other means to arrive at the same end, again anything that is designed to pull the nose down via wind inherently creates drag. Everything else we are working towards with going fast is about reducing drag so why take a backwards step (plus i'm not ready to drill holes in my slalom boards quite yet).

How does it work, I'd say cause of dual surfaces- the water would be acting more alone on the bottom foil shape which is shaped similar to a board's nose but which sits lower and aids in lift for the nose earlier/longer. Pulling the nose down is the whole foil acting with airflow.