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Measuring Waves
Airborne - 18-4-2004 at 14:23

That's a good point! I knew it wouldn't be that big most of the time. What are the mud flaps? I think i might try it out....a messy small wave with sediment can't be as bad as no wave at all!

Do they usually have lifeguards in the summer, or is it not that kinda beach?
Being sort of a novice i need to know what "blow out" means. Is it when there are no waves or what?

Final question! Does 2-3 ft look around this size?


justal - 18-4-2004 at 17:27

LOL

'Blow Out' means that its affected by the wind and gets choppy and messy once thw ind is on it.

2-3 foot is MUCh bigger than the photo you posted...Thats more like 6 inches!!! 2-3 foot surf will give you faces that are just below chest high to head high.

Al.


Airborne - 19-4-2004 at 19:28

Errr....yeah i knew that!
I thought that the wave was a bit small when i posted it...LOL. Why am i laughing again?
Anyway thanks for that definition on "blow out" Al. Yet another question coming up....do you mean chest to head height on a full sized man, because 2-3ft doesn't sound to big?

I think that i need to get my measureing tape out when i go to Croyde again, i'm going crazy!

Cheers all. Airborne.


SinistaPenguin - 22-4-2004 at 14:56

Wave size is a tough one - everyone measures it differently.

Take this conversation for example:

Walking down the beach:

Beginner: "Wow, those waves look pretty big"
Expert: "Nah, that's 1 1/2 maybe 2 feet"

Out back:

Expert (to another guy): "Last time I was down here, it was at least 2 ft bigger and much cleaner"
(to himself) "jeez, this is huge - I'm going to die out here"

Walking back up the beach:

Beginner: "I just don't get it - I'm sure they were more than 1 1/2 to 2 ft"
Expert: "There may have been the odd 3ft 'sneaker set'"

In the Pub:

Beginner: "I dread to think what 6-8ft is like - I was terrified today"
Expert (to his mates): "Man, you should have been there - it was double overhead - at least 12 feet!"

You get the picture!

I tend to gauge it in terms of fear.

NOT AT ALL SCARED (BORED) = probably a little on the small side
NOT SCARED (But having a great time) = small, but super fun
A LITTLE WORRIED (But still having a great time) = a good size
GETTING SCARED EVERY FEW SETS = pushing your limits
TERRIFIED = get out of the water!

This I think is a good rule of thumb, cos then it doesn't matter how big it actually is! It could be that 2ft terrifies you!

Cheers

Sinista


Airborne - 22-4-2004 at 16:06

That's superb. LOL! That's a great way of looking at it. I might try looking at it that way. It's sort of like a lesson, everyone should use it in some respects...but then you get the die hard fans, that have to get it perfect!

I found this thing about how to measure waves. It seems like everyone uses different ways of measureing waves. Why make it confusing? Can't we just all have the same thing and stick to it. Anway here it is:

"Measuring waves:

Here's some funny-but-true info that will keep you from being labelled a "kook".

In the wave riding world, there's sort of a standard to measuring waves that has no basis in anything other than tradition when giving foot measurements. Here's the general rule of thumb when measuring waves:
You may use all the numbers up to 6 feet, but when giving a range of wave size. Example- It was 1-2 feet. It was 3-5 feet. It was 4-6 feet.
Above 6 feet, you may only use even numbers, or multiples of 5. Example- It was 6-8 feet, it was 8-10 feet, it was 10-12 feet, it was 12-15 feet.
You can't say: It was 7-9 feet, it was 11-13 feet...and for some bizarre reason, saying it was 14 feet isn't acceptable. That number is rarely used to measure waves.
Above 20 feet, you only measure waves in increments of 5 feet.

Now, we move on to how to measure waves:
Basically, there are 4 ways that I've learned to measure waves, and that depends on where you are in the world.
East coast USA: Waves are measured using body parts until it gets overhead. Example: It's knee high, stomach high, thigh high, chest high, etc.
West coast USA: Also use body parts, though not as detailed as east coast. West coasters don't use "thigh high", or "stomach high". Face height is typically used to measure waves, the wave's rideable face from trough to crest. Therefore, with an average man being close to 6 feet tall, a head high wave is 6 feet.
Hawaii: 1/2 the face height. Not sure why this is done, but that's just how they do it. There's alot of theories as to why, but who knows. A head high wave in Hawaii is 3 feet.
Australia: These guys have the weirdest method that has been described to me by my Aussie friends as measured by "the powerful part of the wave". So, for example, a mushy head high wave to an Aussie would be about 3 feet, but a top-to-bottom barreling head high wave might be 5 feet. Neither measurement is accurate technically, but that's how they do it. Plus, they measure the swell height in meters anyway.

So, there's "Wave Measurement 101" for those of you still in the learning process. "

Airborne.


SinistaPenguin - 23-4-2004 at 10:22

Hawaiian style is apparent the waves measured from the back - so if you're sitting in the lineup and you look back at the wave you just paddled over, just as it breaks you'd say - 'hey, that's about 3 ft' although if you were looking at the face of the wave, you would see it was about 6 ft!

At least that's what I heard!

Sinista


Airborne - 23-4-2004 at 17:26

That's intersteing about the Hawaiian way of measuring the wave. Hi tim, i'll give you an e-mail about the south west of France if i want and info etc. Cheers, that's great. I'll do that right now in fact! (So check your e-mails!) Does anyone know any surf spots in the south of France? Or near the D-Day beaches in the North?

Thanks. Airborne.


justal - 29-4-2004 at 06:00

Heres some more stuff on measuring waves....

HOW TO MEASURE A WAVE
Written by Ricky Grigg (ultimate big wave & surf legend)
as printed in the Surfers Journal volume 12, number 1, 2003 Ricky Griggs


quote:
Once upon a time, an old Hawaiian surfer told me that those surfers who measure from the back have already missed the wave. Of course, you could argue that surfers who measure the wave from the back do so on purpose so that they can purposefully underestimate their size. But why would anyone want to do that you ask? Perhaps they are the macho guys. "Shucks ma, that overhead wave is only three feet, at least to me. Its no big deal". But then one day a wise guy like me comes along and says, "Three feet, for an overhead wave? What are you anyway, only three feet tall?" The 56" surfer
says, "Huh? What? Are you blind?" "No" I say," maybe you are blind. That overhead wave was way over your fully upright body." "Hey man," he tells me, "you measure waves from the back." I say, "You mean the back of the wave you cant see?" And of course he says, "Right on, dude, right on"

Wish that all this banter was much ado about nothing, but unfortunately it is not. There is a history and a very good reason why so many surfers these days measure from the back. Lets go back about 40 or 50 years in Hawaii and revisit the golden years of surfing and try and find the answer. Back then waves were bigger, bluer, and much less crowded. Surfers at Waikiki rode huge waves all measured from the front. Duke Kahanamokus famous 1.1mile ride had to have been 20"plus when it first broke at first break (out near Castles). Todays surfers would have called it 10 had they been there. Trouble is, had they been there, they would not have been able to see the wave, at least not from the beach. So how did all this back of the wave nonsense get started anyway?

I was surfing the North Shore in those days, the late 50s, 60s and 70s, and what started to happen very slowly over this time period was a gradual tendency to underestimate waves. As it got worse and worse, everyone started realizing that the smaller the estimates were, the smaller the reports were on the radio and TV, and fewer and fewer people were showing up to surf on any given day. Hey, man, this was way cool. A super cool method began to develop to keep the surf a secret. Eight to 10 waves at Sunset slowly became 4-5 with a few pulses. But how in Gods name could anyone call an 8 wave 4, or a 10 wave 5? Not that difficult. The surfers and lifeguards simply invented an new system of measuring the waves from the back. It worked great, because, of course, waves from the back are about half their size from the front. Since few people could actually see the backs of the waves, few people could disagree or claim otherwise. Fewer Townies went to the North Shore and the local guys had the waves all to themselves. The lifeguards liked it too, because they had fewer people to guard and so they could go surfing longer. The system prospered and more and more surfers grew up believing that measuring the waves from the back was the way to do it.

End of story. There were a few old-timers around who remembered the old way, the first way, the simple way, the face-value, from-the-top-to-the-bottom way, from the front, from the crest-to-the-trough, the way oceanographers define wave height, the way in which ordinary people can judge a wave simply by looking at it. By its face value. Not only did the old-timers remember, but they also reminded the lifeguards about safety. It wasnt to safe to broadcast to Hawaiis tourists that 8-10waves were only 4-5. People drowning and getting slammed into the bottom by shorebreak could sue, and guess what, they did sue. A number of visitors throughout the Islands suffered severe neck injuries producing paraplegia and quadriplegia, all caused by shorebreak waves that were larger than those reported. Several cases were settled or won to the tune of millions of dollars. It was not long before the City and County of Honolulu was under a powerful economic and legal gun to change the system back to the old way of measuring waves from the front by the face. This old way is now called the "new" way, because so many young surfers never heard of the old way, until now perhaps.

The "new" has been adopted by the National Weather Service in Honolulu and is now reported by all of Hawaiis news media: newspapers, radio, TV everyone. Even the lifeguards are now reporting face values. A special course in how to measure and report surf was designed by the National Weather Service tailored specifically for the lifeguards of the City and County of Honolulu. Over the course of about 15 months (in 2000 and 2001) about 80 lifeguards successfully completed the class. With this new awareness, the lifeguards have embraced the "new" policy. And, there is no question that their first and foremost concern is safety for Hawaiis visitors and residents alike. Its been a rapid transition back to the old way, the simple way, the safe way, and the HONEST way. Its just like my old Hawaiian friend said, "Never measure the wave you missed. Its the one you
ride that counts"



Al.


Thodd - 29-4-2004 at 07:54

I've always thought that waves were measured from the back? Isn't it something to do with forcasting the swell?
ie... waves out in the sea don't break because the water they are in is to deep... so it could be said that it they don't have a face and both front and back are the same size. When the Bouys are bobbing up and down sending all that scientific data back to scientific places it is that size that they record.

Obviously the Hawaiian way far outdates this way, so everything I just said is rubbish.... but I think it helps make sense of it all!

PS.... If i'm surfing 3ft waves(from the back) i'll always recall the story in the pub later as "they were 6ft". Then depending on how much beer i've had the following words seem to appear aswell;
clean
tubing
glassy

and if I start on the whisky;

"A freakish 10ft set every 15mins or so!"
"I got air"


SinistaPenguin - 29-4-2004 at 15:33

OK. Here's the thing

Waves look different from the beach, to when you're out there.

I posted this on another forum to show how everyone measures differently.

How big is this wave?


Airborne - 29-4-2004 at 19:02

Good question! Can't you just take a meter stick out with you when you surf?


justal - 29-4-2004 at 19:14

It always looks a LOT smaller than it really is from the beach!!

Al.


Thodd - 30-4-2004 at 07:51

I fell for that theory at Croyde Al!!!
It was a VERY low tide... and the waves looked pathetic. We got our kit together walked to the sea... it still looked like rubbish surf...

I paddled out and got an absolute spanking from mother nature! I spent 90% of that session holding my breath underwater !


Airborne - 30-4-2004 at 18:51

LOL! I know what you mean! One time in France near Les Dunes, i think, i found a beach which i went to on a really dull windy day. It was miserable, anyway i turned to my mum and said "it looks a bit small and rubbish, but i might as well go in and try it" (i did this to annoy my brother who wanted to go back to the caravan). The waves were really rough and messy, loads of white water, and it didn't help that i hadn't learned to duck dive yet!
I tried to get out back for about half an hour, but realised that i wasn't getting anywhere because the waves seemed to be bigger than on the shore, the waves/whitewater just kept pushing me back. There was also some crazy current or something where if i paddled forward to try and get "out back" i ended up going sideways without realising. So i ended up quite a far distance away from where my stuff on the beach was. Is there any way i can stop this from happening, any advice to help me keep paddling in a straight line to where my stuff is on the beach?

I just couldn't believe that there was another bodyboarder (fully grown experienced sponger) was out there riding those messy waves...this refers back to my post about bodyboarders liking messy waves as well on another post.


Thodd - 4-5-2004 at 15:07

It sounds like you were caught in a nasty rip tide!
I'm afraid you cannt really stop them as the sea will always be more powerful than you. The worst mistake alot of people make is trying to swim against them..... this will hardley ever work, instead swim sideways to it
I know that its not the easiest thing to do especially if its a sideways rip.

You'll understand them better and how to deal with them, with time and experience.

Sometimes they can be your greatest friend and give you a conveyor belt express route straight out to the back of the line up. Othertimes they can be a pain in the @rse and put you in real danger!


Airborne - 5-5-2004 at 18:02

The thing is Thodd i don't get much experience!
A rip tide sounds about right though! When i tried swimming sideways, it did seem to work...it's just my mum wanted me to stay inside the lifegaurd area because it was pretty rough! By paddling sideways do you mean diagonally to advance forwards a liitle. Or is it paddling at a right angle to the beach to get out the rip tide?


Thodd - 6-5-2004 at 07:39

Basically you need to swim at a right angle to which ever way the rip tide is going. In essence, use the quickest, easiest and safest route to get out of it!


Airborne - 6-5-2004 at 17:03

Oh right i've heard that before many times. Once you get out of the current you can start swimming forward again, right? How can you tell (see) where a current is, what could i look for? Or can you only "feel" the current?
I already know that to paddle out look for bobbing up and down of whitewater, because this is where low pressure is and therefore it is the best/easiest place to duckdive to get out back.

Cheers.


Thodd - 7-5-2004 at 08:14

I use anybody else thats in the sea as a marker to see if i'm moving in a direction that I don't want to be. Also give yourself a marker on the beach (A sand dune etc) this'll tell you if your moving to the side.

If you stand on the beach and look out to sea, you'll see all the breaking waves, in the places where the waves break the least is where there might be a rip. Usually this is on both ends of the beach and there will be one in the middle (possible 2 if its a long beach). Theres a beach I sometimes go to called Hells Mouth in north wales. Its over 2 miles long and as you can guess its rip tide hell!

To duck dive I've always usedone it this way. When the wave is breaking and it lips over. The point on the water were the wave hits as it breaks is the best place to duck dive. If done correctly the force of the wave will "suck" you under and you'll pop out behind it!
......in theory! But the amount of times i've buggered it up and got washed away with massive waves....


Airborne - 8-5-2004 at 15:47

LOL! I must try to perfect my duck diving skills this year...yet again you are the master of advice. Rips, where to duck dive ect. I've even seen pros sort of duck dive in 6 inch white water near the shore to gain a little more time and effort and not to lose speed. There is another type of duck dive thing where your board goes under the wave but your body goes over the top without you getting wet...what is this called again? Isn't something like the "up and over - under" manuver?


Thodd - 10-5-2004 at 09:16

You've got me there Airborne!

I've never seen or heard of a duck dive like that before!

Personally when I'm paddling out I like to power up the face of the wave if I can, if you time it right the "suck" of the wave before it breaks will shoot you in the air and you can do a fancy 360 spin.... its completley pointless but its an amusing thing to do while your swiming out!


Airborne - 12-5-2004 at 19:02

interessting idea! I also like to go over the wave.


mexican bandit - 15-5-2004 at 19:11

Just to go back to measuring waves:

quote:
Originally posted by Thodd
I've always thought that waves were measured from the back? Isn't it something to do with forcasting the swell?
ie... waves out in the sea don't break because the water they are in is to deep... so it could be said that it they don't have a face and both front and back are the same size. When the Bouys are bobbing up and down sending all that scientific data back to scientific places it is that size that they record.
"



Buoy measurements out at sea are swell height, and Thod is almost right as to back and front being the same. There is some small difference.

Swell height is not the actual wave height when these break. Swells are measured out at sea and the height stated (spectral height, effective height or something like that) is the maximum height acheived by the smallest two thirds of the waves of a swell (something to do with energy measurements, etc.).

So once the swell is forced on to a shallow shelf over a short distance the height of the wave may be increased. If it travels over a long softly sloping bottom the wave will lose energy (and height) as it travels along, and in some cases it may never break until it impacts onto a cliff face. So the correct measure of a "ridden wave" should be its face height of the wave in question.

You then go on to measuring real height (straight up) or along the face (join the top and the bottom with a straight line, and measure the line). The latter done with many big waves as it gives more of an idea of how thick it is.


Airborne - 16-5-2004 at 18:40

WOAH! So much info....i sort of get it. Doesn't a waves height also depend on how far the "fetch" is. This is geography GCSE by the way. The "fetch" is the length of water over which wind has blown.

There are two types of wave:
1) Constructive wave - this is a wave which is long in relation to height, it's gentle, is less erosive and is a making wave. By the word "making i mean it carries the sediment/material up to the beach and deposits it, this makes or adds to the amount of material eg. sand on the beack, making it larger. Hence the name "constructive" wave. These waves break on an average of 6-9 per minute.

2) Destructive wave - this is a wave which is high in proportion to length, it is more powerful and more erosive. Instead of "making" it "destroys" by carrying sand and pebbles out to sea, away from the beach. It is powerful so it also errodes cliffs and beaches. Hence the name "destructive" wave. These waves break on an average of 11-15 per minute.

"Swash" is the force of a wave coming towards the beach and "Backwash" is the force of the wave retreating away from the beach. Like a wave motion when it laps up the sand and then retreats again.

In a Constructive wave the swash is greater than the backwash. Therefore if there is less backwash then the lip of a wave won't form because there is still water underneath the lip. In other words the water underneath the unformed lip hasn't been taken away with the backwash leaving an overhanging lip because the backwash is weak.

In a Destructive wave it is the exact opposite. The backwash is greater than the swash. Therefore a lip is formed and the wave becomes a tall breaker. It breaks downwards with power and force.


booger - 12-5-2005 at 10:44

airbone where did that crap about how we measure waves in aus come from? everyone in aus measures in ft and usually the majority of surfers in aus talk down the size which i have been brought up to do and for example a wave with a 5ft face which u guys have been saying is 2-3ft would be in the 1-2ft caterogry in my book and a 6ft wave would have around 12ft plus face. and a 'blow out' is when a wave barrells quickly n heavily and all air inside barrell gets spat out, messy surf is refered to as blown out.


Airborne - 23-5-2005 at 18:45

lol, calm mate
i just heard that from one of the other members on the forum...i think, it was ages ago i cant even remember talking about it...ure right about the blow out, blown out part i must have made a spelling mistake and missed off the "n", weird how you look at waves as smaller, i dont really see any point


Thodd - 26-5-2005 at 08:16

Surely 1 foot = 12 inch. So how can a wave be smaller than it actually is? ie our 2-3ft wave is your 1-2ft wave?

Somewhere between England and Australia we've lost 12 inchs! Maybe the lost inches stopped off at Singapore and missed the connecting flight!


Airborne - 26-5-2005 at 11:38

lol, thats a good point Thodd

and when you think about it 12 inches is around 30cm...so when you hear 2-3 foot they're only 90cm tall, that's 3x30cm rulers...so when you look at it, its not very tall at all, about the height of my desk. But when you hear someone say "3ft tall waves" i seem to think people think its bigger than it actually is. Dont know about making it smaller or not now.


SinistaPenguin - 26-5-2005 at 16:03

I always measure waves by the face.

I thought measuring from the back was 'Hawaiian Style'.

But I have developed my own wave measurement system which takes away the confusion of ft/ metres & front/ back.

It goes like this.

Level 1 - Bugger, it's flat - if I'm desperate I'll get my skimboard out
Level 2 - Am I really that desperate?
Level 3 - Spose it's worth getting suited up
Level 4 - Fun
Level 5 - Superfun
Level 6 - Occasional anxiety
Level 7 - Pushing the envelope
Level 8 - I'm sure it wasn't this big when I paddled out!
Level 9 - Screw that, I aint going out in that
Level 10 - I'm afraid to park my car here in case it gets washed away!!

This usually clears up the confusion!!

Sinista


SinistaPenguin - 26-5-2005 at 16:06

Ah, I appear to have repeated myself a little!!

Ooops sorry!


kelvin - 26-5-2005 at 16:15

all this talk of measurements
bit like my dick , depends who you ask !
you,ll get various opinions on how big it actually is,
i,d say ots huge
er indoors tweeny

and if you measure it from the back , wey ho


Thodd - 27-5-2005 at 09:54

i'm gonna use sinista's scale from now on.
its much easier.


Airborne - 27-5-2005 at 18:04

yeh great idea there sinister


justal - 28-5-2005 at 04:56

quote:
Originally posted by kelvin
all this talk of measurements
bit like my dick , depends who you ask !
you,ll get various opinions on how big it actually is,
i,d say ots huge
er indoors tweeny

and if you measure it from the back , wey ho




If I try measuring from the back the wave usually closes out... It's certainly rare for me to tuck into a nice little barrel anyway! But my backside 0ff-the-lip re-entries are pretty good!



Al.


Airborne - 28-5-2005 at 11:46

lol!

whatever Al

Lets get back to the real subject of this topic. Hehe, I was browsing in the Stormrider Guide Europe and saw this at the front:

Wave face measurements:

huge: 10+m (30+ ft)

triple overhead: 6m (18 ft)

double overhead: 4m (12 ft)

head high and a half: 3m (8ft)

head high: 2m (6ft)

chest high: 1.5m (4ft)

waist high: 1m (3ft)

knee high: 0.5 (2ft)

double over ankle: 0.3m (1ft)

flat: 0m (0ft)

Although this is less fun than Sinisters way, i think its pretty clear and acceptable.

Airborne.


booger - 16-6-2005 at 10:30

no way that is correct, so according to that on tuesday i pulled into a 5m closeout?? reports over here were calling it 8ft+ and face of the wave was around 10-15ft, easily biggest swell ive surfed, but no way i would call it 5m more like 5-6ft (5 because of inconsistency), i think i might talk it down abit mainly because i dont wanna sound like a full blown kook saying i surfed 5m. everyone over here seems to talk it down heaps, dunno why ey.


Airborne - 16-6-2005 at 11:45

LOL! what measurements are using over there in Oz??

5m is tall you know, on www.onlineconversion.com it says 5m = 16 ft...those measurements are scientifically correct, so either Europes measurements are different to yours, or your surfers may be a bit confused.

So the waves you surfed were most likely 5 metres tall, but all this comes down to how u measure it again, back to where we started.


booger - 18-6-2005 at 03:58

airborne the face height of the wave is not how u call wave size.
how big would u fellas call this wave of parko getting slotted off his tit on tuesday??
[IMG]http://img163.echo.cx/img163/2815/14jun006big5xc.jpg[/IMG]


Airborne - 18-6-2005 at 09:11

This is what we've been discussing all this topic, earlier i posted this:

"Now, we move on to how to measure waves:
Basically, there are 4 ways that I've learned to measure waves, and that depends on where you are in the world.
East coast USA: Waves are measured using body parts until it gets overhead. Example: It's knee high, stomach high, thigh high, chest high, etc.
West coast USA: Also use body parts, though not as detailed as east coast. West coasters don't use "thigh high", or "stomach high". Face height is typically used to measure waves, the wave's rideable face from trough to crest. Therefore, with an average man being close to 6 feet tall, a head high wave is 6 feet.
Hawaii: 1/2 the face height. Not sure why this is done, but that's just how they do it. There's alot of theories as to why, but who knows. A head high wave in Hawaii is 3 feet.
Australia: These guys have the weirdest method that has been described to me by my Aussie friends as measured by "the powerful part of the wave". So, for example, a mushy head high wave to an Aussie would be about 3 feet, but a top-to-bottom barreling head high wave might be 5 feet. Neither measurement is accurate technically, but that's how they do it. Plus, they measure the swell height in meters anyway."

That was from an article somewhere...its funny how Australia has the weirdest method I measure wave height by the face size anyway because:

1) its the part that everyone sees
2) you dont have to add on the depth of the water if anyone does that anyway
3) doesnt really include measurement of power

Having said that, i admit i am rubbish at looking at a waves and saying how tall it is. But looking at your picture i would say "judging by the height of those surfers, and the average man being around 6ft i would say that wave face is 10ft where the lip is breaking" lol i might be completly wrong...but then everyone has their own method. Your right, most people might not measure it by face height, me and my friends might be the only ones that do lol.

Judging from the article Aus and UK sound different methods.

Keep posting all.

[Edited on 18-6-2005 by Airborne]

[Edited on 18-6-2005 by Airborne]


booger - 25-7-2005 at 02:35

i came across this text from ben matson a local surf forecaster here about measuring waves

Imperial measurements (ie feet) are much easier to use when speaking about the surf, as it rolls off the tongue a lot better - especially as waves are rarely at convenient metric intervals like 1m, 1.5, 2m.

For example, when was the last time you heard someone coming out of the surf at Snapper, frothing about how there were "absolutely sick one point two five metre barrels"? It's much easier to say that it was "four foot and pumping".

As for how waves are measured.. it's been discussed in these forums (and many others) a million times before. I don't think it really matters at all whether everyone agrees or not. The key point as far (as surf reporting is concerned) is the swell trend and the consistency of the reporter. If someone said that it was 4' today and then they reckon that it's 6' today, then it must be bigger. It's up to you to work out to what degree it has increased - but the most important facor is the swell trend (up, down, weaker, stronger).