Search found 1735 matches

by Cranked
Tue Aug 14, 2018 3:29 pm
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

So you don't know how to calculate the energy of a swell or a breaking wave in joules?

I'm giving up. I'll just accept what Surf Forecast says it is.
by Cranked
Tue Aug 14, 2018 2:32 pm
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

Cranked I think you need to read a bit more about waves in general. You are mixing up ocean waves and breaking waves, and your description of what you think happens when waves break is a bit loony. If 100 cubic metres of water, per metre of shoreline length, was deposited by each 1m high 12s period...
by Cranked
Tue Aug 14, 2018 11:20 am
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

Lucky bastards! So I should check with UWA and Udayana University on the bukit to see if they've got something similar for the Indian Ocean?
by Cranked
Tue Aug 14, 2018 10:24 am
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

I think its a bit alienating for me because its for an area that I don't surf or think about. If it was for the Indian/southern oceans I would probably sit up and pay attention and absorb it all pretty quickly, and remember it.

I assume you have to pay to get that sort of thing though?
by Cranked
Tue Aug 14, 2018 9:56 am
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

This is because I think a swell with say 500kJs will produce similar waves at your local irrespective of whether the swell is 6' at 9s or 2' at 15s, and etc for larger kJ swells. Overall, all you need to know for most surfs is whether its under 500 (marginal for surfing) or 1000, 2000, 3000 or 4000...
by Cranked
Tue Aug 14, 2018 9:41 am
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

Well you can do what I propose or you can read this: Here's a fully calibrated forecast from the best forecaster in the world, daylight second: Pat Caldwell. DISCUSSION: SUMMARY... Short-period N swell dropping with long-period S swell rising into the weekend. DETAILED:. Mid Friday on northern shore...
by Cranked
Tue Aug 14, 2018 9:34 am
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

Here's the case for kJs in a nutshell. There seems to be agreement that surf forecasts are not very good at forecasting the size of breaking waves at specific surf spots but are pretty good at forecasting the prevailing swell height and period for an area. So its up to us to know what a specific swe...
by Cranked
Tue Aug 14, 2018 6:50 am
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

BA wrote:
Mon Aug 13, 2018 4:08 pm
Image
Lets nip these stupid implied comparisons in the bud BA. Waves don't have any trans or saturated fats and are much better for you, just pure unadulterated energy.
by Cranked
Mon Aug 13, 2018 8:29 pm
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

Can someone please do a similar calculation for MM throwing a good haymaker punch.
This is more the sort of thing that would fix the concept of kinetic energy in nicks mind
by Cranked
Mon Aug 13, 2018 7:54 pm
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

It’s pretty obvious. A joule is equal to the energy transferred to an object when a force of one newton acts on that object in the direction of its motion through a distance of one metre (1 newton metre or N⋅m). Or in other words kg * m 2 / s 2 ; where kg is the kilogram, m is the metre, s is the s...
by Cranked
Mon Aug 13, 2018 5:22 pm
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

Am I getting the hang of it..? 200kJ - barely breaking, get out your log = 1 foot 500kJ - surfable, use your twinny = 2 foot 1000kJ - have fun on your small wave board = 3 foot 1500kJ - good overhead surf = 4 foot 2000kJ - really good head and a half, some doubles = 4-6 foot 2500kJ - consistently o...
by Cranked
Mon Aug 13, 2018 5:01 pm
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

nah it's fine, 2000 calories? most of us would walk that off. it is actually the thing that's been troubling me about all this fcuken Kilojoule talk though. What does it mean? Does it mean how much energy passes a certain point in a certain time? Does it mean the energy contained in some portion of...
by Cranked
Mon Aug 13, 2018 4:21 pm
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

No. Around Perth the offshore reef blocks most of the swell but the surf forecasts don't take this into account. I usually just convert the metres on the forecasts to feet, that is if the swell is 3m I'll assume its 3' faces. Because of refraction around the reef gaps even a 3m swell is pretty much...
by Cranked
Mon Aug 13, 2018 4:02 pm
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

200kJ - barely breaking, get out your log 500kJ - surfable, use your twinny 1000kJ - have fun on your small wave board 1500kJ - good overhead surf 2000kJ - really good head and a half, some doubles 2500kJ - consistently overhead, frequent doubles 3000kL - lots of doubles, some bigger 3500kJ - only t...
by Cranked
Mon Aug 13, 2018 3:49 pm
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

Cranked 8470 kj forecast for Lennox head next Monday. any idea what that means? Some set waves with 20' faces. I probably wouldn't go out. If I did I would be nervously and constantly scanning the horizon and paddling for it whenever I saw a distant shadow that might be the one hour set wave on its...
by Cranked
Mon Aug 13, 2018 9:57 am
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

I assume its the same as the error margins for swell height and period as that is what its derived from
by Cranked
Mon Aug 13, 2018 9:26 am
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

No. Around Perth the offshore reef blocks most of the swell but the surf forecasts don't take this into account. I usually just convert the metres on the forecasts to feet, that is if the swell is 3m I'll assume its 3' faces. Because of refraction around the reef gaps even a 3m swell is pretty much ...
by Cranked
Mon Aug 13, 2018 9:05 am
Forum: General surf discussion
Topic: Just general surfing stuff
Replies: 4205
Views: 322903

Re: Just general surfing stuff

I think thats why I like using kJ, the swell/wave energy with no reference to height. Its then up to me to convert that to wave heights at a particular break if I want to. After about 5 years using it now I usually don't.

Unless I'm talking to someone who doesn't use it.