How to judge wave heights when it gets big

caml's picture
caml started the topic in Tuesday, 8 Dec 2015 at 9:42pm

Knowing how to call wave size correctly once the waves are bigger than you are familiar with . Theres no way of finding out without experience because photos & film make it look so much smaller than it really was . I have been learning my whole life how to make a call on correct Hawaiian size traditional . There are famous stories of everyone thinking Hawaii was the only place to find 25ft surf ( pre todos & mavs ) then they found out for real . Growing up in Margaret river the general call on a big day surf was 12ft and it was cool too say that but it was wrong . But I didn't know it at the time . Its really a negative car park surfer or something like this that started it . By learning the buoy & surfing the reefs off Margarets I started to work out formulas for the waves & reefs . Something about this , For example . [email protected] = 10ft sets , 3m @18 would produce 15ft sets ,
4m @ 18 will give 20ft sets .
5m @18 25ft,
6m @18 - 30ft . .
But in hawaii the waters deeper & the reefs focus swell better than margarets . Wave size will be bigger due to the bathymetry . Not to mention todos,mavs,cortes,nazare,dungeons ,& more breaks where the bathymetry is more favorable than Margarets for xxl waves . This discussion was inspired by my desire to teach craig ( my friend) & others how big the jaws comp was & because I see it regularly by the swellnet forecasts undercalling xxl swells & friends who look at pictures of big waves & underestimate the size . So the swell at jaws : wasnt it 5m plus @17 ,[email protected] etc ? Immediately that means about 25ft without even adjusting my scale from margs to Hawaii due to bathymetry ! All these swells around the world on average are 4-5-6 m with 16-22 sec periods that produce easily 25ft surf .

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caml commented Tuesday, 8 Dec 2015 at 9:44pm

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caml commented Wednesday, 8 Aug 2018 at 6:57pm

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caml commented Wednesday, 8 Aug 2018 at 6:57pm

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crip's picture
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crip commented Tuesday, 8 Dec 2015 at 10:55pm

Totally agree that pix undersize waves. Not that i have ever been in properly big waves ( "man's gotta know his limitations"- dirty harry).
But...
It's always irked me that people can't just call a wave for its actual size - ie. face height. Anything else is just fiction, or some esoteric value that calls in various factors including water depth, swell period, ego, testosterone, blah blah.
Trying to work out a formula is just nonsense.
Sorry Camel.

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southey commented Tuesday, 8 Dec 2015 at 11:30pm

I lost a lengthy post ...
But I'll retry .
Personally every wave I've ridden has felt smaller than what photos have shown . Mind you cameras don't show often in the parts I like to frequent . With the excpetion of big barrels waves to me always seem smaller when riding them than scratching for the shoulder or getting caught inside . Maybe it's just my vision .
I think we are de -sensitised by tow surfing with guys on small boards making it look bigger than guys paddling on massive guns .
As for raw swell heights , I've been out of my depth and seriously undergunned a few years ago in 6.3/6.8 M ?!? @ 19 or 21 sec's . And that day I was told by somone older with far more experience including Hawaiin , that it was 15 ft . Admittedly that swell angle didn't concentrate onto the reef , and elsewhere was probably 20ft plus .
Crip that is exactly why people should talk swell heights not wave heights . The power involved is calculatable by height by period . How hollow I'd probably the third variable , but that is definitely easily recognisable . The big thing I think that is lacking is swell speed . And probably this is where Camel is heading . Until someone works out a way of accurately measuring the swell hitting a reef then we will have our measurement nirvana .

" SA's Reserve Capacity "

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Rabbits68 commented Wednesday, 9 Dec 2015 at 12:16am

I agree with Crisp. If this thread is about measuring pure wave height then surely it's cut & dry, simply measure the wave face.

Southey with all due respect but you've already complicated the thread by introducing other variables. I'm not suggesting that these variables don't necessarily affect wave height (your knowledge seems far superior to mine in this field) but wave height is wave weight, power & hollowness aside. It is what it is. A standard measure in feet is required, from a particular point at the base of the wave to the apposing point at the peak etc.

Why not ask the blokes that were charging this recent Hawaiian swell. See how many variable answers we get from these guys (if any) & why.

A great topic to discuss for sure.

Crystal Clear

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wally commented Wednesday, 9 Dec 2015 at 12:27am

I just think of wave height as a measure of how tall the wave is. That does not define how big and heavy the wave is, except possibly in relation to other days at the same break.
We all know that tall does not, as a general rule, perfectly correspond with destructive power for anything.

Caml, it seems you want wave feet to be a measure of more than vertical height. You want the wave feet measure to also reflect the mass and the speed of the water. The forceful energy of the wave. I reckon that's fine, but that's not 'feet'.

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Craig commented Wednesday, 9 Dec 2015 at 6:23am

Thanks Cam, totally understand where you are coming from.

But while those estimated wave heights you've given for the swell sizes and periods are on the mark, each location and reef etc will deal with the incoming swell differently.

Regarding calling the size, everybody has slightly different scales, but I think if you're consistent in you're sizes, people can then align themselves to that and get a true idea of how big it is.

I subscribe the commonly used scale of 3ft = head high, 6ft = 2x overhead etc and 20ft = 40ft faces.

In line with you and opposite to Southey, I agree with that photos make the wave look smaller than it felt yourself on it, but this might just be mental perception.

It's a big can of worms calling wave height, but as I said above, I think the key lies in consistency.

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crip commented Wednesday, 9 Dec 2015 at 9:02am

Yeah, now I understand what you're getting at Camel.

But calling wave height based on swell height & period only works for regions, or maybe deep water offshore reefs. It does not work for individual breaks.

So I rock up at Bells and it's a cranking 8-10ft (faces). Double overhead. Craig would be calling it 6ft. Macho men might call it 4ft coz they're heroes. But with that swell, around at Fishos might be 2ft. Barely knee-high. Craig would call it 1ft? But down at Port Campbell, it's BIG. 20ft. 4x overhead. Craig calls it 10ft. Then the swell jumps. Doubles in size. Down there it's now 40-50ft faces. Craig calls it 20-25ft. But others are calling it 15-20.

There was a thread on this some time ago, and it seems that it's acceptable to have a sliding scale, where as it gets bigger, the increments in what it's called get smaller.

If I get to a break, I want to be able to say that it was x ft. Not have to look up a swell chart to find out what the swell height & period is.

As you say Craig, consistency is the key, across regions, breaks and sizes.

Oh, and the waves are double the height when you're caught just in front of the impacting lip ;-)

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goofyfoot commented Wednesday, 9 Dec 2015 at 10:12am

I agree with pretty much every thing you say there crip, apart from the bit if bells had 8-10ft faces Craig would be calling it 6ft. I don't think he would, or would I. It would be 4-5 ft. You can't call a wave with a 8ft face 6ft. A 6ft wave would have roughly a 10-12ft face. IMO.
All the rest is spot on I reckon. I'm not trying to nit-pick either, just saying my opinion

tux's picture
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tux commented Wednesday, 9 Dec 2015 at 10:48am

Crap
Small
Big
Bigger
I'm undergunned you go

These are the only measurements in my book

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freeride76 commented Wednesday, 9 Dec 2015 at 10:55am

Not wanting to weigh into the old wave measurement argument but just curious about Caml's call that it was the biggest Jaws ever paddled.
Seemed like Doz, Greg Long, Rowley and others had paddled equivalent or bigger waves.
And Albee Layer called it a 3/10 on the day....so he obviously didn't rate it as the "day of days".

Whats been the call from the guys who surf it all the time? Biggest ever paddled? Or just an awesome day of paddle-in big wave riding?

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batfink commented Wednesday, 9 Dec 2015 at 11:16am

The only thing I have to add is that to get a reasonable idea you must be at water level. Photos taken from any height above the water result in parallax view error and will definitely lead to size being under-called. the great thing about Peahi is all the water craft in the channel, many of them taking photos.

A day some time ago, I'm thinking last year or early this year, where Dorian was just carving it up on a virtually windless and big day had some of the best surfing shots you could hope for.

But all you have to go on from the pics is the size of the surfer and the board he is riding, which are known, and the height of the wave face, which has to based on the two known factors. Caml, I'm sure the camera does lie, but it would not be distorting the surfers and boards relative to the wave face. that is, both would be distorted by the same factor, so the relativity remains.

What I can't imagine is just what it looks like when you are taking off on one of those beasts, rising to your feet as the lip grabs you and you have a sheer drop below you. I suspect that vision is priceless. :-)

Only a mad man knows the feeling!

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caml commented Wednesday, 8 Aug 2018 at 6:59pm

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Gary G's picture
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Gary G commented Wednesday, 9 Dec 2015 at 12:58pm

Seems like the solution here is units.
I can recommend a rock solid unit: The Gary.

One Gary is solid
Two Gary's is some serious size
Three Gary's and you've got a party

You and me, Gary, ain’t nothing but mammals so let’s do it* like they do it on the aerobics channel

*faceys

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caml commented Wednesday, 8 Aug 2018 at 7:00pm

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pointy's picture
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pointy commented Wednesday, 9 Dec 2015 at 1:00pm

Gary G wrote: Seems like the solution here is units.
I can recommend a rock solid unit: The Gary.

One Gary is solid
Two Gary's is some serious size
Three Gary's and you've got a party

yeah but a Garry (two R's) is bigger than a Gary

Craig's picture
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Craig commented Wednesday, 9 Dec 2015 at 2:10pm

Images from Camel..

The tow vs paddle shows they were paddling bigger waves this event than they used to tow!

Damon Eastough Cows vs Billy Kemper Jaws

Billy Kemper and Greg Long Jaws

Tow vs paddle at Jaws

Mark Mathews

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caml commented Wednesday, 8 Aug 2018 at 7:01pm

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caml commented Wednesday, 8 Aug 2018 at 7:02pm

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mick-free commented Wednesday, 9 Dec 2015 at 9:44pm

Mick Free FIFOFOMO

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mick-free commented Wednesday, 9 Dec 2015 at 9:54pm

Caml here is the data. I haven't had a chance to read the thread yet just scanned down.

This is the 01 buoy approx 14-15 hours from Maui. Go off the HAST times (bottom). So the peak is 20 feet at 17 secs at 2-3pm dropping fairly quickly. Add travel time and peak was approx 5am with Surfline calling 40 - 60 feet wave faces. Which was inline with the waves caught pre-comp.

I can't upload this video but maybe Craig can

https://www.instagram.com/p/-9R_bBQZtQ/?taken-by=donkeyshow

People who have been there maybe able to put a figure on it.

Good luck with wave heights debate, you're opening a can of worms haha.

Mick Free FIFOFOMO

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mikehunt207 commented Thursday, 10 Dec 2015 at 12:23am

If somebody rides a giant wave and nobody takes a photo of it was it still ridden? That is the question.
I like Craigs headheight =3ft and so on.
Lots of size difference variations in the angle photo is taken from, look at Jaws pics from the water shots for a truer size angle rather than the cliff same goes for Waimea .
Nobody could have paddled Eastoughs Cow wave, not then not now no matter how great they paddle, how many lifejackets they wear or how much money is up for grabs. Jaws has a more surfable/rideable face shape at that size than CB, same with all the waves in Hawaii compared to WA, totally different ocean floor shape, hawaii is just mountains sticking up out of the ocean so the revines become the channnels, WA is deep coming into chunks of shallow , less perfect (in many ways).
Good thread.

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caml commented Wednesday, 8 Aug 2018 at 7:02pm

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caml commented Wednesday, 8 Aug 2018 at 7:03pm

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caml commented Wednesday, 8 Aug 2018 at 7:03pm

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thermalben commented Thursday, 10 Dec 2015 at 1:53pm

Camel, using raw buoy data to estimate surf size is fraught with difficulties. Across the southern Australian states, large swell events are often heavily contaminated with local windswell - so the standard metrics of Hsig, Hmax and Tsig or Tz won't reflect the true value of groundswell in the water. 

Additionally, the WA buoy data is proceesed in a slightly unconventional manner, to produce a non-standard output (they do this by truncating the spectral data at 11 seconds to produce 'swell waves' and 'sea waves'). I've spoken with Dept Transport about this problem many times over the last ten years, but it's out of their control (the processing is done by ocean/met software company Tremafon).

Therefore, when using your formula for Cape Naturaliste and Cow Bommie against Cape du Couedic and Yanerbie, you're not really comparing apples with apples. 

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Craig commented Thursday, 10 Dec 2015 at 1:54pm

Yeah that is about right Cam, here's both the swell height and period together..

I'd agree with 25ft bomb sets, but most waves being in the 15-20ft range.

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caml commented Wednesday, 8 Aug 2018 at 7:04pm

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caml commented Wednesday, 8 Aug 2018 at 7:04pm

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carpetman commented Thursday, 10 Dec 2015 at 2:06pm

Hey Craig,

What is "Dominant" period? I'm assuming it's average period but why use the word dominant? Unless its the dominant directions average period?

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caml commented Wednesday, 8 Aug 2018 at 7:05pm

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Craig commented Thursday, 10 Dec 2015 at 2:16pm

Dominant Period is the same as Peak Period.

And the peak was around 6pm the evening before at this buoy, 51101, which is some 500km from the North Shore (approx 10hr travel time) and 690km from Maui (approx 13hr travel time).

Each little notch is 4 hours, so 12 hours between each label on the bottom axis. HAST is Hawaii time, ie 14 HAST is 2pm Hawaii Time.

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caml commented Wednesday, 8 Aug 2018 at 7:06pm

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caml commented Wednesday, 8 Aug 2018 at 7:07pm

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seal commented Thursday, 10 Dec 2015 at 3:57pm

I also believe photos can make the surf look smaller than it was / is and this can be for a number of reasons. The angle, especially if taken from the same plane as the wave , often won't show how much of a trough has been made by the wave drawing the water off the reef/bank.
Also quite often the surfer turns 2/3 of the way down to the bottom of the wave rather than running all the way to the flats which can also make the wave look smaller.
Photos can also fore-shorten the image which can also distort the size ratio of the wave and surfer.
The biggest I've ever had the courage to surf was what the Hawaiians were calling 8-10ft but I would have called 15-20ft and was happy to make it in in one piece. There was so much water moving around, peaks shifting , cleanup sets etc and certainly looked and seemed at lot bigger in person than it did on any photos I saw of the day. But of course this could also be our own perception and fear coming into play, though, you often hear people remark how it seemed bigger than the photos of most peoples larger surf sessions.
I'd love to be out there one day in a safe place and watch something as big as Jaws break but be stuffed if I'd have the fitness, skill and guts to take that stuff on!!

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thermalben commented Thursday, 10 Dec 2015 at 3:58pm

Sure, they're not the only buoys that get contamination. But it needs to be taken into consideration. 

Re: WA buoys - they don't display time series graphs of Tp and Tsig, or Hsig. Most forecast techniques involve calibrating model predictions against recorded observations. But the models don't forecast "swell height" and "sea height" - they forecast either individual swell trains, or significant wave heights. So in WA there's no way to know if the swell is higher or lower that forecast expectations. 

My main gripe with the WA buoys is the lack of graphed Tp though. The CdC, Sorell and Nepean buoys will often record Tp of 20+ seconds, yet I've never seen any WA buoys higher than about 16 seconds (for their "swell period"). Again, this is another calibration technique to assess just how high core wind speeds were. If Tp comes in earlier and higher than modeled, then you know core wind speeds were stronger and you can recalibrate your forecast based on this information.

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Gary G commented Thursday, 10 Dec 2015 at 4:11pm

pointy wrote:
Gary G wrote: Seems like the solution here is units.
I can recommend a rock solid unit: The Gary.

One Gary is solid
Two Gary's is some serious size
Three Gary's and you've got a party

yeah but a Garry (two R's) is bigger than a Gary

Touche, and you know I like nothing more than a measuring contest

You and me, Gary, ain’t nothing but mammals so let’s do it* like they do it on the aerobics channel

*faceys

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braudulio commented Thursday, 10 Dec 2015 at 7:05pm

Know whatcha mean G-love, nothing like getting the ruler out!

‘IF YOU UNDERSTAND, things are just as they are;
if you do not understand, THINGS ARE JUST AS THEY ARE.’

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wellymon commented Thursday, 10 Dec 2015 at 8:51pm

thermalben wrote:

I've spoken with Dept Transport about this problem many times over the last ten years, but it's out of their control

Wow Ben never knew, big 32 wheeler trucks were involved let alone motorbikes and cars;)

maybe tell them to slow down and get a speed which is what Caml wants, with bathymetry........

Our brains are too small at the moment to comprehend the reality of what's happening in our forests . We're only just waking up so to speak . The big problem is we think we know everything, we are specks of dust on a timeline and we know nothing .

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tonybarber commented Thursday, 10 Dec 2015 at 9:26pm

Gents, given the multitude of variables in swell height and buoy locations, contamination, local environment factors, can't there be an agreed measurement method at the location it breaks ?
So if camera shots are taken at angles, it should not be too hard to work out any parallax errors and thus correct. The lip is relatively well defined whereas the base would need to be defined.
But I must admit, I do like the 'hawaiian' height - generally conservative ?

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braudulio commented Thursday, 10 Dec 2015 at 10:04pm

For those interested in a more quantitative approach check this out (sorry for NSW only):

http://www.nswaves.com.au/

‘IF YOU UNDERSTAND, things are just as they are;
if you do not understand, THINGS ARE JUST AS THEY ARE.’

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caml commented Thursday, 10 Dec 2015 at 11:21pm

Nice piece of work braudulio.

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caml commented Thursday, 10 Dec 2015 at 11:22pm

Tb yes thats right I think near enough

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caml commented Thursday, 10 Dec 2015 at 11:26pm

Craig wrote:

Yeah that is about right Cam, here's both the swell height and period together..

I'd agree with 25ft bomb sets, but most waves being in the 15-20ft range.


So pretty much 5.5m @17 sec at dawn with howling offshores . Thanks for the info craig
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caml commented Wednesday, 8 Aug 2018 at 7:09pm

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penmister commented Friday, 11 Dec 2015 at 1:16am

That helicopter looks like there could be 5 of em stacked on top of each other in that bomb..imagine if you could tell a wave bye the hold down? Maybe 2min under vs 2min above...camel is the jedi...

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thermalben commented Friday, 11 Dec 2015 at 8:58am

caml wrote: I don't understand this jargon
Just so we're on the same page, what data are you looking at on the WA buoys? Using today's data (below), what numbers are you referencing?


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thedrip commented Friday, 11 Dec 2015 at 9:59am

Thermalben: I don't understand all the technical stuff you were saying, but that WA swell buoy is generally pretty adequate for me. Today's data tells me at one of the waves I regularly surf it will be 4-5 with the very very odd 6 footer. At another joint it will be 3-4. It's knowledge of what that data translates to at particular waves that Camel is talking about I believe.

And, referring to an earlier post, the buoys do go above 18. Some of the bigger waves we get consistently are driven by ramps in swell period and not necessarily swell height. I'm talking 6-10 rather than huge swells so 2-2.5 but with 18-20sec periods. That happens reasonably regularly over Autumn/winter.

I also agree with Camel that blokes in the southwest start getting nervous about calling anything over 12 foot. At my local Bombie it will three times over head (I am 6'2") and the boys will be calling it four foot. How does that work?

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thedrip commented Friday, 11 Dec 2015 at 10:00am

And the data I was referring too was the slightly updated version I looked at about five minutes before my reply. I was annoyed I couldn't surf.