This article is within the scope of
WikiProject Canoeing and Kayaking, a project which is currently considered to be inactive.Canoeing and KayakingWikipedia:WikiProject Canoeing and KayakingTemplate:WikiProject Canoeing and KayakingCanoeing and Kayaking articles
International scale of river difficulty is within the scope of the WikiProject Water sports, a collaborative effort to improve Wikipedia's coverage of
Water sports. If you would like to
participate, you can visit the
project page, where you can join the project and see a list of
open tasks.Water sportsWikipedia:WikiProject Water sportsTemplate:WikiProject Water sportsWater sports articles
I wrote this on my own using several sources as a guide.
Jordanmills 22:48, 30 January 2006 (UTC)reply
I am compiling a similar article and only just found yours. I'll just add my details to this one instead ;). See my
Sandbox for the work in progress.
Needs editing?
Rivers are graded by the hardest/most technical section on the river. I.e. the river could be virtually flat up to a waterfall, the waterfall could be grade 4 and so the river would be grade 4.
Just thought this would be usefull for you to know, but I will not edit this as I do not have much knowledge of editing wikis. —The preceding
unsigned comment was added by
165.84.1.72 (
talk) 03:44, 13 May 2007 (UTC).reply
I don't think this is accurate, if the river is flat water with one class IV drop it is usually marked I(IV) signifying that the river as a whole is class I with the hardest feature being class IV
Heard.james (
talk) 20:39, 22 May 2009 (UTC)reply
Photos illustrating grades
We could do with some better photos illustrating grades in my opinion. The current grade 3 and grade 5 shots are particularly poor illustrations, because ideally the photos should all be taken at approximately the same eye-level above the river, and approximately equal distance from the rapid concerned. That way it will offer a much better comparitive illustration. Someone kayaking down the rapid will help to show scale too.
I just swapped out the grade six photo because someone had put a my photo of Guile Triple-step in there, which is not a grade six rapid. It's grade 5. I've paddled it myself!
Rhine Falls is undisputably grade six though (it being the biggest waterfall in Europe!) But ideally we have one which is a more reasonable size river, but still grade 6, and with somebody in it somehow to illustrated scale.
I agree with you on the pics for grades 3 and 5. I selected all these pics when I reformatted the article. But unfortunately we are limited to the available photos on Commons. Some new ones may need to be taken... Note that even if a river has been run, at high levels it may become unrunnable. This needs to be taken into account before categorically stating that a rapid is grade 5 just because it has been run. --
P199 (
talk) 21:36, 25 April 2008 (UTC)reply
Surely a better grade 6 photo, would be Niagara/Victoria falls or a heinous large volume rock strewn siphon fest? :) The first two are easier to get images of, however.
Jamsta (
talk) 22:07, 25 April 2008 (UTC)reply
I think the Grade 4 photo is misleadingly easy, typically an open canue without float bags paddled by people without helmats does not make it very far down a class IV river. I will try to upload some of my own footage into the commons soon.
Heard.james (
talk) 15:40, 22 May 2009 (UTC)reply
This picture is of the Crooked Chute on the
Petawawa River which is officially classified as a grade 4. So the picture is appropriate but granted, it is of poor quality. --
P199 (
talk) 12:39, 25 May 2009 (UTC)reply
International?
I wonder why this is called "International scale" when it looks like American :-) In Europe (at least Austria, Czech Republic, Germany, Poland, Slovak Republic from my own experience) it is used the same as described within "Australia and New Zealand" section, i.e. Grade VI "at the limit" (but still possible). In addition, "ZW" grade describes waters easier than WW I. (In the past, there were ZW A, ZW B and ZW C ratings, with A being steady water and C a flow running up to 10-12 km/h but without waves; these are not used now, which is a pity because the speed of travel on ZW A and ZW C differs a lot, and if you want to estimate the time needed to sail something down ...) --
77.48.82.162 (
talk) 22:23, 8 November 2008 (UTC)reply
Oops, sorry to Americans, I did not check the "Specific location/national classifications" section thoroughly and it seemed to me that for US it is the same as the table in the section "Classification" which says Class VI (or U) = Unrunnable, but it is not true, the US version section does not classify WW VI as unrunnable. Now I really wonder where the "International" version comes from, as at least three continents (North America, Europe and Australia) use the same ("German") system, which is different from what is called "International" within the article? --
77.48.82.162 (
talk) 07:40, 9 November 2008 (UTC)reply
My understanding of the issue is that the "International Scale of River Difficulty" is the American system for rating rapids throughout the world, and not a list of international rating systems for rapids. See
http://www.americanwhitewater.org/content/Wiki/safety:internation_scale_of_river_difficulty for the background and history. This means there are a couple of directions this article can go. (1) We remove all the misc scales about the India rating system, the duplicated US rating system, etc and just have this be a stub of a larger article focusing on rapid rating systems. (2) We change this page to be "Scales of River Difficulty" and break the scales down by region. (3) there might be other options I am not considering, so please chime in. One thing to consider is that if we go with option 1, we will probably want to create those other pages.
Ryanx7 (
talk) 16:42, 12 March 2014 (UTC)reply
I don't have time to now, but I'll definitely have a think and weigh in about this!
Did a bit of googling, I was trying to find out if the
International Canoe Federation had anything to say... and saw this:
[1] it's a decent length article with quite a few sources at the end that I hope will add something, again, I'll have a proper think later!
Jamesmcmahon0 (
talk) 19:04, 12 March 2014 (UTC)reply
per that article too, the
American Whitewater scale-- aka the
International Scale of River Difficulty-- seems to be one of the most popular with lots of international derivatives. That said there are others that are very different. The Grand Canyon, for example, has a rating system that ranges from Class I to Class X. I am leaning towards the idea of just having this article focus on American Whitewater's International Scale of River Difficulty. Then creating a new section that speaks to the fact that many similar evolutions of this scale. We could then add things like non-derivatives to new stub articles (Example
Grand Canyon Rating Scale ) Thoughts?
Ryanx7 (
talk) 19:30, 12 March 2014 (UTC)reply
I agree with your assessment, I think this article should be renamed to reflect the American origin of the 'International scale' at the moment the international bit (and how the article is written) makes it sound like an international standard rather than an American made and created scale that happens to be used a lot around the world. I think sections in this article for minor variations, such as calling them grades vs classes also how class VI is treated. Any scale that deviates in more than a minor way should get its own article.
There is an argument to create an overarching umbrella article of
White water difficulty classification that summarises all variations throughout the world (similar to how this article does now but without such a confusing name) though I think this might lend too much weight to the non-American scales which are, internationally speaking, more niche.
Jamesmcmahon0 (
talk) 10:39, 13 March 2014 (UTC)reply
→Okay so lets start by archiving/deleting the "Specific location/national classifications" section and adding a see also section that could point at other classification scales. I'll start working on citing and clarifying the lead section to clarify the bit about this being the American scale for evaluating rivers throughout the world (and speak to the fact other scales have been based on it)
Ryanx7 (
talk) 21:15, 13 March 2014 (UTC)reply
→Also just to clarify, I do not think we should rename this article to remove the "international" part. The official name of the scale is the "International Scale of River Difficulty."
Ryanx7 (
talk) 22:50, 13 March 2014 (UTC)reply
Rename?
I propose that "International" should be dropped from the page title.
The word does not add much.
The word is debatable.
Which international body has adopted the scale?
(Does paddling actually have an international body?)
Can we also think of a way to indicate what the scale refers to?
Avoid canoeists - others use the scale too.
See my comments in the international section above re the name change
Ryanx7 (
talk) 16:54, 12 March 2014 (UTC)reply
Archived section
Per our discussion above I have archived this section. If there is interest in creating articles on the specific scales used in other regions this information is accessible here.
Ryanx7 (
talk) 22:47, 13 March 2014 (UTC)reply
Specific location/national classifications
Ratings can differ somewhat from country to country.
Grade I: Rapids have small regular waves. Easy passage, but care may be needed with obstacles.
Grade II: Rapids have many medium sized waves (less than 1 Meter), Low ledges or drops, easy eddies and gradual bends. The passage is easy to recognize and is and generally unobstructed.
Grade III: Rapids have fairly high waves (1–2 meters tall), broken water, strong currents and eddies, large holes, exposed rocks and small falls. The passage may be difficult to recognize from on the river and maneuvering around obstacles is required to negotiate the rapid. Still relatively easy.
Grade IV: Difficult Rapids that have High, powerful, irregular waves, broken water, often boiling or strongly recirculating eddies, strong powerful hydraulics, ledges, drops and dangerous exposed rocks. The passage often difficult to recognize and precise sequential maneuvering is required. A definite risk of injury or long swims exists.
Grade V: Very powerful rapids, with very confused and broken water, massive waves, large drops, violent and fast currents, abrupt turns, difficult powerful stopper hydraulics, Many dangerous exposed rocks and fastly boiling terminal eddies. There are numerous obstacles in the main current, including dangerous, possibly life threatening hazards. The extreme for commercial operations. Complex, Precise and powerful sequential maneuvering is required for safe passage. A definite risk to personal health and safety exists.
Grade VI: Extremely dangerous, classified as unraftable. All previous difficulties increased to the limit of practicability. Very confused, Very Violent, Exploding and folding water so difficult that controlled navigation by raft is virtually impossible. Swimming this grade of rapid is considered suicidal. Requires extreme luck or skill to finish.
Grade II: Mainly clear passages; some areas of difficulty
Grade III: Difficult passages; narrow in places and with high waves
Grade IV: Very difficult, narrow and requiring precise maneuvering
Grade V: Extremely difficult. Very fast-flowing waters which can be maneuvered only by experts
Grade VI: For all practical purposes, unmanageable - even suicidal
United States
The following is an expanded, more detailed version of the international scale from
American Whitewater, the publisher since 1955 of American Whitewater Journal:[1]
Grade I: Fast moving water with riffles and small waves. Few obstructions, all obvious and easily missed with little training. Risk to swimmers is slight; self-rescue is easy.
Grade II: Straightforward rapids with wide, clear channels which are evident without scouting. Occasional maneuvering may be required, but rocks and medium-sized waves are easily missed by trained paddlers. Swimmers are seldom injured and group assistance, while helpful, is seldom needed. Rapids that are at the upper end of this difficulty range are designated Class II+.
Grade III: Rapids with moderate, irregular waves which may be difficult to avoid and which can swamp an open canoe. Complex maneuvers in fast current and good boat control in tight passages or around ledges are often required; large waves or strainers may be present but are easily avoided. Strong eddies and powerful current effects can be found, particularly on large-volume rivers. scouting is advisable for inexperienced parties. Injuries while swimming are rare; self-rescue is usually easy but group assistance may be required to avoid long swims. Rapids that are at the lower or upper end of this difficulty range are designated Class III- or Class III+ respectively.
Grade IV: Intense, powerful but predictable rapids requiring precise boat handling in turbulent water. Depending on the character of the river, it may feature large, unavoidable waves and holes or constricted passages demanding fast maneuvers under pressure. A fast, reliable eddy turn may be needed to initiate maneuvers, scout rapids, or rest. Rapids may require “must” moves above dangerous hazards. Scouting may be necessary the first time down. Risk of injury to swimmers is moderate to high, and water conditions may make self-rescue difficult. Group assistance for rescue is often essential but requires practiced skills. A strong
kayak roll is highly recommended. Rapids that are at the lower or upper end of this difficulty range are designated Class IV- or Class IV+ respectively.
Grade V: Extremely long, obstructed, or very violent rapids which expose a paddler to added risk. Drops may contain large, unavoidable waves and holes or steep, congested chutes with complex, demanding routes. Rapids may continue for long distances between pools, demanding a high level of fitness. What eddies exist may be small, turbulent, or difficult to reach. At the high end of the scale, several of these factors may be combined. Scouting is recommended but may be difficult. Swims are dangerous, and rescue is often difficult even for experts. A very reliable kayak roll, proper equipment, extensive experience, and practiced rescue skills are essential. Because of the large range of difficulty that exists beyond Class IV, Class 5 is an open-ended, multiple-level scale designated by class 5.0, 5.1, 5.2, etc... each of these levels is an order of magnitude more difficult than the last. Example: increasing difficulty from Class 5.0 to Class 5.1 is a similar order of magnitude as increasing from Class IV to Class 5.0.
Grade VI: These runs have almost never been attempted and often exemplify the extremes of difficulty, unpredictability and danger. The consequences of errors are very severe and rescue may be impossible. For teams of experts only, at favorable water levels, after close personal inspection and taking all precautions. After a Class VI rapids has been run many times, its rating may be changed to an appropriate Class 5.x rating.
This article is within the scope of
WikiProject Canoeing and Kayaking, a project which is currently considered to be inactive.Canoeing and KayakingWikipedia:WikiProject Canoeing and KayakingTemplate:WikiProject Canoeing and KayakingCanoeing and Kayaking articles
International scale of river difficulty is within the scope of the WikiProject Water sports, a collaborative effort to improve Wikipedia's coverage of
Water sports. If you would like to
participate, you can visit the
project page, where you can join the project and see a list of
open tasks.Water sportsWikipedia:WikiProject Water sportsTemplate:WikiProject Water sportsWater sports articles
I wrote this on my own using several sources as a guide.
Jordanmills 22:48, 30 January 2006 (UTC)reply
I am compiling a similar article and only just found yours. I'll just add my details to this one instead ;). See my
Sandbox for the work in progress.
Needs editing?
Rivers are graded by the hardest/most technical section on the river. I.e. the river could be virtually flat up to a waterfall, the waterfall could be grade 4 and so the river would be grade 4.
Just thought this would be usefull for you to know, but I will not edit this as I do not have much knowledge of editing wikis. —The preceding
unsigned comment was added by
165.84.1.72 (
talk) 03:44, 13 May 2007 (UTC).reply
I don't think this is accurate, if the river is flat water with one class IV drop it is usually marked I(IV) signifying that the river as a whole is class I with the hardest feature being class IV
Heard.james (
talk) 20:39, 22 May 2009 (UTC)reply
Photos illustrating grades
We could do with some better photos illustrating grades in my opinion. The current grade 3 and grade 5 shots are particularly poor illustrations, because ideally the photos should all be taken at approximately the same eye-level above the river, and approximately equal distance from the rapid concerned. That way it will offer a much better comparitive illustration. Someone kayaking down the rapid will help to show scale too.
I just swapped out the grade six photo because someone had put a my photo of Guile Triple-step in there, which is not a grade six rapid. It's grade 5. I've paddled it myself!
Rhine Falls is undisputably grade six though (it being the biggest waterfall in Europe!) But ideally we have one which is a more reasonable size river, but still grade 6, and with somebody in it somehow to illustrated scale.
I agree with you on the pics for grades 3 and 5. I selected all these pics when I reformatted the article. But unfortunately we are limited to the available photos on Commons. Some new ones may need to be taken... Note that even if a river has been run, at high levels it may become unrunnable. This needs to be taken into account before categorically stating that a rapid is grade 5 just because it has been run. --
P199 (
talk) 21:36, 25 April 2008 (UTC)reply
Surely a better grade 6 photo, would be Niagara/Victoria falls or a heinous large volume rock strewn siphon fest? :) The first two are easier to get images of, however.
Jamsta (
talk) 22:07, 25 April 2008 (UTC)reply
I think the Grade 4 photo is misleadingly easy, typically an open canue without float bags paddled by people without helmats does not make it very far down a class IV river. I will try to upload some of my own footage into the commons soon.
Heard.james (
talk) 15:40, 22 May 2009 (UTC)reply
This picture is of the Crooked Chute on the
Petawawa River which is officially classified as a grade 4. So the picture is appropriate but granted, it is of poor quality. --
P199 (
talk) 12:39, 25 May 2009 (UTC)reply
International?
I wonder why this is called "International scale" when it looks like American :-) In Europe (at least Austria, Czech Republic, Germany, Poland, Slovak Republic from my own experience) it is used the same as described within "Australia and New Zealand" section, i.e. Grade VI "at the limit" (but still possible). In addition, "ZW" grade describes waters easier than WW I. (In the past, there were ZW A, ZW B and ZW C ratings, with A being steady water and C a flow running up to 10-12 km/h but without waves; these are not used now, which is a pity because the speed of travel on ZW A and ZW C differs a lot, and if you want to estimate the time needed to sail something down ...) --
77.48.82.162 (
talk) 22:23, 8 November 2008 (UTC)reply
Oops, sorry to Americans, I did not check the "Specific location/national classifications" section thoroughly and it seemed to me that for US it is the same as the table in the section "Classification" which says Class VI (or U) = Unrunnable, but it is not true, the US version section does not classify WW VI as unrunnable. Now I really wonder where the "International" version comes from, as at least three continents (North America, Europe and Australia) use the same ("German") system, which is different from what is called "International" within the article? --
77.48.82.162 (
talk) 07:40, 9 November 2008 (UTC)reply
My understanding of the issue is that the "International Scale of River Difficulty" is the American system for rating rapids throughout the world, and not a list of international rating systems for rapids. See
http://www.americanwhitewater.org/content/Wiki/safety:internation_scale_of_river_difficulty for the background and history. This means there are a couple of directions this article can go. (1) We remove all the misc scales about the India rating system, the duplicated US rating system, etc and just have this be a stub of a larger article focusing on rapid rating systems. (2) We change this page to be "Scales of River Difficulty" and break the scales down by region. (3) there might be other options I am not considering, so please chime in. One thing to consider is that if we go with option 1, we will probably want to create those other pages.
Ryanx7 (
talk) 16:42, 12 March 2014 (UTC)reply
I don't have time to now, but I'll definitely have a think and weigh in about this!
Did a bit of googling, I was trying to find out if the
International Canoe Federation had anything to say... and saw this:
[1] it's a decent length article with quite a few sources at the end that I hope will add something, again, I'll have a proper think later!
Jamesmcmahon0 (
talk) 19:04, 12 March 2014 (UTC)reply
per that article too, the
American Whitewater scale-- aka the
International Scale of River Difficulty-- seems to be one of the most popular with lots of international derivatives. That said there are others that are very different. The Grand Canyon, for example, has a rating system that ranges from Class I to Class X. I am leaning towards the idea of just having this article focus on American Whitewater's International Scale of River Difficulty. Then creating a new section that speaks to the fact that many similar evolutions of this scale. We could then add things like non-derivatives to new stub articles (Example
Grand Canyon Rating Scale ) Thoughts?
Ryanx7 (
talk) 19:30, 12 March 2014 (UTC)reply
I agree with your assessment, I think this article should be renamed to reflect the American origin of the 'International scale' at the moment the international bit (and how the article is written) makes it sound like an international standard rather than an American made and created scale that happens to be used a lot around the world. I think sections in this article for minor variations, such as calling them grades vs classes also how class VI is treated. Any scale that deviates in more than a minor way should get its own article.
There is an argument to create an overarching umbrella article of
White water difficulty classification that summarises all variations throughout the world (similar to how this article does now but without such a confusing name) though I think this might lend too much weight to the non-American scales which are, internationally speaking, more niche.
Jamesmcmahon0 (
talk) 10:39, 13 March 2014 (UTC)reply
→Okay so lets start by archiving/deleting the "Specific location/national classifications" section and adding a see also section that could point at other classification scales. I'll start working on citing and clarifying the lead section to clarify the bit about this being the American scale for evaluating rivers throughout the world (and speak to the fact other scales have been based on it)
Ryanx7 (
talk) 21:15, 13 March 2014 (UTC)reply
→Also just to clarify, I do not think we should rename this article to remove the "international" part. The official name of the scale is the "International Scale of River Difficulty."
Ryanx7 (
talk) 22:50, 13 March 2014 (UTC)reply
Rename?
I propose that "International" should be dropped from the page title.
The word does not add much.
The word is debatable.
Which international body has adopted the scale?
(Does paddling actually have an international body?)
Can we also think of a way to indicate what the scale refers to?
Avoid canoeists - others use the scale too.
See my comments in the international section above re the name change
Ryanx7 (
talk) 16:54, 12 March 2014 (UTC)reply
Archived section
Per our discussion above I have archived this section. If there is interest in creating articles on the specific scales used in other regions this information is accessible here.
Ryanx7 (
talk) 22:47, 13 March 2014 (UTC)reply
Specific location/national classifications
Ratings can differ somewhat from country to country.
Grade I: Rapids have small regular waves. Easy passage, but care may be needed with obstacles.
Grade II: Rapids have many medium sized waves (less than 1 Meter), Low ledges or drops, easy eddies and gradual bends. The passage is easy to recognize and is and generally unobstructed.
Grade III: Rapids have fairly high waves (1–2 meters tall), broken water, strong currents and eddies, large holes, exposed rocks and small falls. The passage may be difficult to recognize from on the river and maneuvering around obstacles is required to negotiate the rapid. Still relatively easy.
Grade IV: Difficult Rapids that have High, powerful, irregular waves, broken water, often boiling or strongly recirculating eddies, strong powerful hydraulics, ledges, drops and dangerous exposed rocks. The passage often difficult to recognize and precise sequential maneuvering is required. A definite risk of injury or long swims exists.
Grade V: Very powerful rapids, with very confused and broken water, massive waves, large drops, violent and fast currents, abrupt turns, difficult powerful stopper hydraulics, Many dangerous exposed rocks and fastly boiling terminal eddies. There are numerous obstacles in the main current, including dangerous, possibly life threatening hazards. The extreme for commercial operations. Complex, Precise and powerful sequential maneuvering is required for safe passage. A definite risk to personal health and safety exists.
Grade VI: Extremely dangerous, classified as unraftable. All previous difficulties increased to the limit of practicability. Very confused, Very Violent, Exploding and folding water so difficult that controlled navigation by raft is virtually impossible. Swimming this grade of rapid is considered suicidal. Requires extreme luck or skill to finish.
Grade II: Mainly clear passages; some areas of difficulty
Grade III: Difficult passages; narrow in places and with high waves
Grade IV: Very difficult, narrow and requiring precise maneuvering
Grade V: Extremely difficult. Very fast-flowing waters which can be maneuvered only by experts
Grade VI: For all practical purposes, unmanageable - even suicidal
United States
The following is an expanded, more detailed version of the international scale from
American Whitewater, the publisher since 1955 of American Whitewater Journal:[1]
Grade I: Fast moving water with riffles and small waves. Few obstructions, all obvious and easily missed with little training. Risk to swimmers is slight; self-rescue is easy.
Grade II: Straightforward rapids with wide, clear channels which are evident without scouting. Occasional maneuvering may be required, but rocks and medium-sized waves are easily missed by trained paddlers. Swimmers are seldom injured and group assistance, while helpful, is seldom needed. Rapids that are at the upper end of this difficulty range are designated Class II+.
Grade III: Rapids with moderate, irregular waves which may be difficult to avoid and which can swamp an open canoe. Complex maneuvers in fast current and good boat control in tight passages or around ledges are often required; large waves or strainers may be present but are easily avoided. Strong eddies and powerful current effects can be found, particularly on large-volume rivers. scouting is advisable for inexperienced parties. Injuries while swimming are rare; self-rescue is usually easy but group assistance may be required to avoid long swims. Rapids that are at the lower or upper end of this difficulty range are designated Class III- or Class III+ respectively.
Grade IV: Intense, powerful but predictable rapids requiring precise boat handling in turbulent water. Depending on the character of the river, it may feature large, unavoidable waves and holes or constricted passages demanding fast maneuvers under pressure. A fast, reliable eddy turn may be needed to initiate maneuvers, scout rapids, or rest. Rapids may require “must” moves above dangerous hazards. Scouting may be necessary the first time down. Risk of injury to swimmers is moderate to high, and water conditions may make self-rescue difficult. Group assistance for rescue is often essential but requires practiced skills. A strong
kayak roll is highly recommended. Rapids that are at the lower or upper end of this difficulty range are designated Class IV- or Class IV+ respectively.
Grade V: Extremely long, obstructed, or very violent rapids which expose a paddler to added risk. Drops may contain large, unavoidable waves and holes or steep, congested chutes with complex, demanding routes. Rapids may continue for long distances between pools, demanding a high level of fitness. What eddies exist may be small, turbulent, or difficult to reach. At the high end of the scale, several of these factors may be combined. Scouting is recommended but may be difficult. Swims are dangerous, and rescue is often difficult even for experts. A very reliable kayak roll, proper equipment, extensive experience, and practiced rescue skills are essential. Because of the large range of difficulty that exists beyond Class IV, Class 5 is an open-ended, multiple-level scale designated by class 5.0, 5.1, 5.2, etc... each of these levels is an order of magnitude more difficult than the last. Example: increasing difficulty from Class 5.0 to Class 5.1 is a similar order of magnitude as increasing from Class IV to Class 5.0.
Grade VI: These runs have almost never been attempted and often exemplify the extremes of difficulty, unpredictability and danger. The consequences of errors are very severe and rescue may be impossible. For teams of experts only, at favorable water levels, after close personal inspection and taking all precautions. After a Class VI rapids has been run many times, its rating may be changed to an appropriate Class 5.x rating.