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Unregistered
8th December 2009, 09:14 AM
How come I see guys in the magazines planing when there are no whitecaps, and they aren't even on big boards or big sails?

Is it:
a) They are anorexic and weigh about 20kg?
b) New sails and boards are better than my 5-8 year old sails? (surely not!)
c) the photographer has cunningly kept the breakwater out of shot and it is actually 20 knots?

I saw one photo and it said the wind was 4 knots and he was using a sail like 5.6m or something and he was shredding massive waves. How would you even sail out there let alone get cranking fast enough to catch a wave... am I missing something or is it just because Im Australian?

Per
8th December 2009, 08:47 PM
Nothing on this planet planes with a 5.6 in 4 knots... Maybe an Apollo with 12 m2 and a 50 kg rider pumping seriousely...
I think the photographers know a few tricks combined with very good sailors (and at least 10 knots).

;-)
Per

Ken
8th December 2009, 10:14 PM
In Windsurf Magazine I have noted that in some of the photos of wave sailors, they detail the wind speed plus sail and board sizes. For example, wind - 10-12 knots and a X brand 5.6 sail on x brand board at 80 liters. I fail to see how these guys can get outside the surf line in such light winds, small sail/board and surf.

I have done a little surf sailing along the Texas gulf coast and know that it is impossible to do the above even if you only weigh 70 kg.

What gives?

Farlo
9th December 2009, 12:07 AM
You would be surprised by what some sailors can achieve. I remember Eric Thieme doing loops at l'Almanarre with 4 sqm while everybody else was hardly planing with 5. This been said, there were withecaps everywhere that day. On other occasions you can have ~14 knts of wind, which is enough for lightweight sailors to plane on small gear, without noticeable whitecaps depending on spot orientation.

Jean-Marc
9th December 2009, 03:14 AM
Interesting what some image editing softwares can do to "claims" that are not supported by true and tested hard facts and evidences carried out on the water...

Planing in 4 knots wind is BS all the way, no matter what the sail size or board type is. A dedicated planing hull starts to plane at 7-8 knots hull speed, i.e., when the wetted surface is dramatically reduced to the last 40-50 cm of the hull that is in contact with water and when the hull climbs and pass over her own bow wave. Typically, there is a sudden speed surge from the 4-5 knots "schlogging state" to the 7-8 knots "planing state" when GPS speed diagrams are scrutinized by computer analysis softwares. BTW, a Formula can start and sustain the planing as of 6-7 knots of wind with no whitecaps in sight. This usually requires a 11-12 m2 jumbo sail and a lot of pumping skills.

The only explanation of "planing in 4 knots of wind" is in DTL conditions where the energy of the wave and not that of the wind actually pushes the hull to a full planing state. No big deal : surfer do that all the time in 0 wind...

Cheers !

JM

Darko_Z
9th December 2009, 04:42 AM
It can be very misleading if you try to judge wind speed from video or photo. Once I took video of windsurfers in closed bay, it was offshore wind. I took measurement with wind speed meter 2 min average was 36kn, peak 45kn. But on the video it looks like the wind was less than 30kn, there were no big waves because it was closed bay. Most windsurfers were 90kg+ using 4mē sails, but this could not be seen from this perspective. Than I went on the other side of the bay where I could get light at another angle and it looked like 50kn.

Farlo
9th December 2009, 04:28 PM
Hi Darko, this happens in real life as well. Presently our local lake is lower than usual. This results in irregular wind but also less chops/withecaps that you would expect for similar windspeed. Last month we had several weekends with 18+ Knts where water remained strangely quiet, apart from occasional 25+ periods. Everyone was planing, sometimes in survival mode. I guess it can happen at sea by offshore wind, low tide... Now I don't think magazines purposedly select such conditions to promote/claim planing in next to no wind.

kiwiben
15th December 2009, 12:22 AM
thanks everybody, it's the original poster of this thread here (I'm not Australian after all, just used their reputation to hide my own incompetence) I am loving all your comments, keep em coming.

i was out the other day in "surging" wind of 5kts-30kts surges with one other guy and he was getting up and planing ridiculously early compared to me as each new surge started.

he was on a little fanatic 80litre B&J with a 5.2 sail. me on my 121Carve with a 5.9m sail. Only other difference was his weight, about 20kg lighter. (me being 100kg)

The good news is though, once I got up I had top speed way above him, and could haul back his 150m lead in about 600m of water. Go figure? Any comments?

joe_windsurfer
15th December 2009, 06:06 AM
i don't know ...
linkin incompetence to auzzie and rockin to kiwis
ya better watch out :)

Ken
15th December 2009, 09:18 PM
White caps form at 10 knots. Open water, semi-protected water, protected water - the caps still form at 10 knots, it's the size that varies. Open ocean water, the waves/swells are about 1 meter height with a 5 meter wave length. In protected water, the waves/swells could be 3 cm high with a 10 cm wave length.

This may or may not be the actual proportions, just my recollection from numerous observations and some very basic knowledge of waves. I am no expert.

The cap is a small piece of white water breaking off the top of the wave. So when you look at protected water in 10+ knots of wind, and don't see white caps, look closer because they are probably there.

Also, in protected water, the wind speed 1-2 meters off the surface may be higher than what it is at the surface, so a sail could have 10 knots of wind in it while the wind speed at surface is less than 10 knots. No caps to be seen, but the board has enough wind to plane.

BelSkorpio
16th December 2009, 01:53 AM
Hi,

I'm just back from Sal, Cabo Verde. I saw Josh Angulo surf in Ponta Preta (you know, the PWA wave spot in february). There was about 12-13 knots of wind, offshore, also bearly no whitecaps. I passed him, fully planing, on slalom equipment ( 115L board + 8.1 rig) just behind huge waves of +3m. He was on wave equipment with a 5.7m rig (yes, that small), schlogging around just behind the waves. Now Josh is quite a bit heavier than me. You should see him when he catches one of those giant waves. I don't understand how he does it. It almost seems that the rig is of no importance anymore. Unbelievable how he rides those waves. I guess he uses all power of the waves. Damn he's good.

kiwiben
16th December 2009, 06:09 AM
sorry joe, won't happen again... promise

thanks belskorpio and the guy before, i am fast coming to the conclusion that, unbelievable as it may seem, there are windsurfers out there who are actually more talented than me... a bit of a bombshell...

Your whitecap comments all make sense. A little duckpond can be in 30 knots and have no whitecaps.

On the contrary too, sometimes "Whitecap speak with forked tongue." Sometimes I drive up to a spot, see tons of whitecaps and get ultra aroused instantly, erecting my most manly rig as fast as humanly possible and sprinting into the water. My arousal is quickly deflated when i find myself slogging submarinally at half a knot in wind of about 8 knots... bummer dude...

carlosgp5
17th December 2009, 12:04 AM
From the beaufort scale, from 7 to 10 knots, one should start to see whitecaps...
What I think is that it depends on the distance that the wind is running on the water surface. Lets say, off-shore 10 knots: no whitecaps close to shore, but if you go 1 mile out, youre gonna see them; Now if you have an on-shore of 10 knots, itīll be coming from far of the coast, and there will be a lot of it...
Also, the state of the water will depend on how much time the wind has been blowing for; half an hour of 6 knots on shore, no whitecaps. 6 knots blowing for 2 hours, sure you will see it.

Ken
17th December 2009, 01:40 AM
After seeing carlosgp5's post, I looked a little deeper. It seems that all the "white cap" formation information on the web is based on the Beaufort scale and they all say that at Force 3 (7-10 knots), white caps begin to form. I don't know if it is at the bottom or top end of the range, but if there is a specific wind speed in knots where caps begin to form, it would be good to know. I have always used the 10 knot rule, but if caps form in less than 10 knots, it would be interesting to know the exact wind speed.

Farlo
17th December 2009, 05:30 PM
Hi Ken, most probably it can't be related to a single factor (i.e. windspeed). You won't see whitecaps on a speed canal even with 50 Knts blowing. There are no whitecaps when there are no caps (not enough wave height). I guess time, temperature, density, water length & depth... play a role as well.

Unregistered
17th December 2009, 08:56 PM
Like said before (Jean Marc / SKorpio) what you can do in waves breaking on a reef, is slog around the waves to the back of the waves and then use the wave to get planing. Start with leaning forward like surfers do. With hardly any pressure in the sail. You need waves breaking on a reef so you also have a nice quite part which you can use to get out there. In places like Sylt it would be almost impossible.

Ken
17th December 2009, 09:15 PM
Farlo,

I agree that there are several factors that play a roll in developing white caps, but if you look at all the youtube videos on speed sailing, there are plenty of white caps in the speed canals that pop up with only a couple of meters of fetch. The canals are filled with caps. Exactly my point in my first post. Wavelets can cap even if only a few centimeters high.

The video below is an example. While this isn't a canal, it shows how little fetch is necessary for caps to form if there is enough wind. However, I doubt that there would be caps along the shoreline if the wind was 10 knots, but they will form, the only question is how much fetch is necessary to create caps in 10 knots.

http://www.youtube.com/watch?v=aWyzkZFy7HI&NR=1

Farlo
17th December 2009, 10:52 PM
Hi Ken, in this one whitecaps are much less noticeable: http://www.youtube.com/watch?v=ugBXkpfHw7o&NR=1
Another factor that may play a role is sunlight. Sometimes you see plenty of whitecaps, then there is a cloud coming and all of a sudden you see much less. (Of course whitecaps are still there, but if this can trick your eyes, it will more surely trick photos or videos). Anyway I remember sunny days with strong offshore wind, certainly more than 10 Knts, and no whitecaps even 100 meters away from the beach. Could very well be that the necessary fetch for 10 Knts to blow whitecaps is several hundred meters, as Carlosgp5 suggests. Anyone with some model?

Jean-Marc
18th December 2009, 02:47 AM
Interesting discussion going on here...!

For basic ocean wave formation, please check fluid dynamics theory at http://en.wikipedia.org/wiki/Ocean_surface_wave.

Breaking waves appearing in the form of whitecaps over the sea surface is a wind-driven feature that occurs at a wind speed greater than about 4 m/s (> 8 knots or > 3.5 Bft). Below that wind speed, whitecaps are simply not observed.

Whitecap coverage of sea surface is proportional to both wind duration and fetch.

As wind blows over the sea surface greater than about 4 m/s, a "whitecap" of bubbles and streaks is created on the breaking crest of an ocean surface wave. Whitecaps are formed when large numbers of bubbles produced by a wave rise to the surface, and the bright white area of a whitecap arises from multiple light scattering by elements of size comparable to or greater than the wavelength of visible light. These elements are clusters of proximate, closely packed bubbles at or near the surface of the breaking crest of an ocean surface wave (source http://www.springerlink.com/content/j0647331h845710t/).

So to answer the initial question, yes, it is possible to start and sustain the planing in the absence of clearly visible whitecaps. Formula can do that as of 6-7 knots of wind speed. However, it is impossible to start and sustain the planing as of 4 knots of wind with any type of windsurfing gear, except when the forward motion is provided by the power of a wave pushing the surfing hull down the line.

Cheers !

JM

vikingsail
18th December 2009, 09:33 PM
There is one other consideration why you may not see whitecaps on photographs or videos. If the photographer is upwind from the sailor the whitecaps are on the backside of the waves; they're hiding. Remember the rule onshore winds rig larger then the water appears, offshore winds rig smaller.