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Upshur
06-13-2016, 08:15 AM
My row on the Maumee Saturday was in some standing waves. Interesting creatures. Where are the largest standing waves located?

Upshur
06-13-2016, 08:24 AM
Standing waves? ya, when you get wind blowing directly against a current .

mmd
06-13-2016, 08:48 AM
Nova Scotia is a small province with small rivers, so the standing waves in our rivers are correspondingly small. The largest I know if is on the Lahave River just above Bridgewater. When the river is in spring freshet, the standing wave at Cook's Falls (rapids, really, with a misnomer in the name) is about a meter to a meter-and-a-half tall.

Reynard38
06-13-2016, 08:54 AM
How about over 50,000 feet? That's how high a sailplane has risen while riding one near Minden Nevada.

http://www.sierranevadageotourism.org/content/glider-rides-soar-above-the-sierra-nevada/sieDDD6C765822CA5522

Gerarddm
06-13-2016, 08:54 AM
Saw an article that a famous pro surfer has created/invented a perfect artificial wave.

Upshur
06-13-2016, 09:20 AM
How about over 50,000 feet? That's how high a sailplane has risen while riding one near Minden Nevada.

http://www.sierranevadageotourism.org/content/glider-rides-soar-above-the-sierra-nevada/sieDDD6C765822CA5522
Reminds me of my soaring days dreaming about soaring across America , staying over Pikes Peak till the next days’ cloud streets kicked in.

Reynard38
06-13-2016, 09:27 AM
Reminds me of my soaring days dreaming about soaring across America , staying over Pikes Peak till the next days’ cloud streets kicked in.

You ever read Sierra Sierra?

David G
06-13-2016, 09:37 AM
ya, when you get wind blowing directly against a current .

That's one way to get a standing wave. Another - which others have alluded to - is when flowing water interacts with certain bottom featured. Rocks in a river. Ocean reef at the right tidal state.

P.I. Stazzer-Newt
06-13-2016, 10:46 AM
Deadman's on the Orinocco is big

But this is unreal

https://www.youtube.com/watch?v=lc7KG1T62n4

David G
06-13-2016, 10:54 AM
PI - that's some ugly chit. Happy to stay on shore there.

P.I. Stazzer-Newt
06-13-2016, 11:17 AM
An Oldie - but goody.

I first saw this on 16mm with some of the best big water paddlers in Britain - about thirty six years ago.


http://www.youtube.com/watch?v=1fWx9iP7ZJU

Upshur
06-13-2016, 11:52 AM
You ever read Sierra Sierra?
No , but thanks, I’ll pick it up. Need to line up some reads for this Fall. Is it cool?

Daniel Noyes
06-13-2016, 12:09 PM
ya, when you get wind blowing directly against a current .
Wind created "standing waves" are different from Rapids, "standing waves"

wind generated appear where the current is flowing against the wind, in effect creating a Fetch for the waves to build ocross that is much longer than the actual distance across the body of water.

with a current speed and wind speed that are matched Waves have an effectively Infinate distance to build along and waves of the maximum height for that wind speed can be observed. The larger the wave the faster it travels so as wind speed increases and wave height/speed increases then you need a faster current to make them standing waves.

When ocean swells enter a river mouth with fast flowing current the phenomea that affects standing waves can be seen when the large ocean waves pile up and steepen their faces.

I was once on the Spirit of Massachusetts at the mouth of the Merrimack river when the bowsprit whent through a wave and 2+ ft of water came over the bow, exciting :)

http://198dodge.com/schooner/album/slides/Spirit%20of%20Massachusetts.JPG

Reynard38
06-13-2016, 12:39 PM
No , but thanks, I’ll pick it up. Need to line up some reads for this Fall. Is it cool?

Its been many years since I read it, but yeah it's pretty good. Fictional wave flight from the PNW to Yuma.

Dan McCosh
06-13-2016, 12:45 PM
There is one on the Detroit River, formed mainly by the current, that can six be inches or so over a half-mile, which causes problems for unlimited hydroplanes running at 180 mph or so.

Kevin T
06-13-2016, 12:54 PM
Saw an article that a famous pro surfer has created/invented a perfect artificial wave.

That story is somewhere right here in the Bilge I believe. It's a story on the Kelly Slater Wave Company at a "secret" location somewhere in central California. Google Kelly Slater Wave Company, it is unreal.

David G
06-13-2016, 01:03 PM
Here ya go -- http://forum.woodenboat.com/showthread.php?200710-Kelly-Slater-perfect-man-made-wave&highlight=the+perfect+wave

Chip-skiff
06-13-2016, 01:03 PM
The tallest standing waves I've seen were in the Grand Canyon, on the the order of 12-14 ft. or larger, depending on stage.

This one, in Crystal Rapid, is infamous for flipping boats.

http://www.outsideonline.com/sites/default/files/styles/three-quarter-page-scaled-1x/public/migrated-images/grand-canyon-crystal-river_fe.jpg?itok=pwvYEdra

Here's another shot of the big wave in Crystal Rapidó

http://web.mst.edu/~rogersda/grand_canyon_research/Crystal%20'83-3.jpg


There are also big waves in Hermit and on Lava Falls, which is a steep drop. I paddled a 12 ft. solo cat down the Canyon. From a boat that small, the waves look even bigger. Took five swims, one pretty serious (they call it getting maytagged).

Chip-skiff
06-13-2016, 01:19 PM
Another rare phenomenon is sand waves. I've encountered them only once while boating, on the lower San Juan River in Utah. When there's enough current force to mobilize a sand bed, the rapidly moving "dunes" cause waves to break at the surface. As I recall, these waves move upstream and are not large, 1-2 ft., but friends have flipped canoes hitting them.

Here's a low-resolution video—


https://www.youtube.com/watch?v=Mr0crHdHTJw

The most common locations for sand waves are in streams that traverse a steep beach: they run at high velocity over a mobile sand bed. I've got some videos from Keam Strand in Ireland, but don't know how to post them. So here's a shot off the web—

https://i.ytimg.com/vi/zgesmtodrUM/maxresdefault.jpg

ahp
06-13-2016, 02:55 PM
These look to be the same as tidal bore. When water flows in a trough, or a river bed, the flow can be described in a third order equation with three solutions. One solution is imaginary and meaningless. The other two are real, fast and shallow, and slower and deeper. The volume must be the same for these two. There can be a stationary or even a moving transition from one solution to the other. That is the standing wave.

You might try to model this with a piece of gutter and a garden hose.

Nicholas Scheuer
06-13-2016, 03:26 PM
The only standing wave we've encountered is the one in the passage past Woods Hole between Vineyard Sound and Buzzards bay. It measured about a half-meter when we went through last time.

john welsford
06-13-2016, 04:42 PM
Driving around the Brooklin Maine area in Carl Cramers pickup, exploring and looking at scenery so different to where I come from, I crossed a bridge with a torrent roaring out under it. Stopped and walked back, there is a fair sized salt pond and the tide goes in and out through a very narrow channel under that bridge, the tides there being what they are there is a lot of water on the move through there.
The standing wave at the bottom at half tide ebb, is pretty big, I'm told that kayakers go there to play.
Not the biggest I've seen but one of the more interesting.

John Welsford

Peerie Maa
06-13-2016, 04:51 PM
These look to be the same as tidal bore. When water flows in a trough, or a river bed, the flow can be described in a third order equation with three solutions. One solution is imaginary and meaningless. The other two are real, fast and shallow, and slower and deeper. The volume must be the same for these two. There can be a stationary or even a moving transition from one solution to the other. That is the standing wave.

You might try to model this with a piece of gutter and a garden hose.
By a moving transition, do you mean a wave train that runs up against the flow before each successive wave dissipates? The fishermen of Morecambe Bay recognise both stationary standing waves and a wave train that stays in the same place whilst the waves move against the current. They call these Running Gillimers, whilst the stationary crest is just a Gillimer.

Ian McColgin
06-13-2016, 05:02 PM
"Standing wave" is applied to two different phenomena: Wind caused waves whose speed matches an opposing current and thus stay in about one place; and a wave in place caused by the action of the current over the bottom, as often found in rivers and streams. Both these are profoundly different from a tidal bore which is a moving "wave" caused by a flood tide forced into a constricted channel.

CK 17
06-13-2016, 05:16 PM
How about over 50,000 feet? That's how high a sailplane has risen while riding one near Minden Nevada.

http://www.sierranevadageotourism.org/content/glider-rides-soar-above-the-sierra-nevada/sieDDD6C765822CA5522
Here is an attempt at 100,000 feet

http://www.perlanproject.org/missions


another great book about mountain wave. . .

http://s20.postimg.org/x3cj741z1/image.jpg

Hugh Conway
06-13-2016, 05:18 PM
These look to be the same as tidal bore.

the wave chip-skiff pictured isn't the same as a bore - because the bottom sand is moving changing the wave position. e.g the wave position relative to the bottom bump is fixed, but the bottom bump position is moving. lagoon dams being breached are a good place to see them.

AnalogKid
06-13-2016, 07:33 PM
How about the Corryvreckan - I heard the standing waves being mentioned in a TV programme about the Inner Hebrides but couldn't recall the size stated, but found this...


However when there is any serious wind strength, particularly from the west, the up-thrusts at the pinnacle fold into the oncoming waves and accentuate them. Thus building, in gale force conditions, standing waves that can be 8, 10 or 15 feet high.

https://www.geocaching.com/geocache/GC18P21_in-a-spin-corryvreckan-earthcache?guid=40dcfbf3-0d15-45e5-aad5-776db1cdb862

http://www.hebridean-wild.co.uk/images/heb-wild/219m.jpg