Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 19-08-2013, 06:09   #1
Registered User

Join Date: Mar 2011
Location: Caribbean
Boat: Oyster 66
Posts: 973
Wierd sea state - perhaps Internal Waves?

This photo was taken last Tuesday at noon about 20Nm north of Trinidad heading south. There were what I would describe as several rivers in the sea. The 'rivers' were about half a mile wide, oriented east/west and longer than I could see. The sea state in the rivers was almost calm, with no white caps. I saw 3 or 4 of them in an area of 6 miles or so. The predominant sea state was of about 4 foot waves with a bit of swell. 16-20kt easterly wind.

There was also what seemed to be a substantial influx of river water in this area as seen by a much greener colour of the sea. I wonder if this came from the Orinoco?

They might have been Internal Waves as described here:
Photo-iss034e032377

Any ideas?
Attached Thumbnails
Click image for larger version

Name:	DSC00389_.JPG
Views:	197
Size:	144.0 KB
ID:	65720  
__________________

__________________
poiu is offline   Reply With Quote
Old 19-08-2013, 06:35   #2
Nearly an old salt
 
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
Re: Wierd sea state - perhaps Internal Waves?

looks like a rip current, could be tidal, a river etc

dave
__________________

__________________
Check out my new blog on smart boat technology, networking and gadgets for the connected sailor! - http://smartboats.tumblr.com
goboatingnow is offline   Reply With Quote
Old 19-08-2013, 06:43   #3
CF Adviser
Moderator Emeritus
 
Hud3's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: Virginia
Boat: Island Packet 380, now sold
Posts: 8,929
Images: 49
Re: Wierd sea state - perhaps Internal Waves?

The Antilles Current is pretty fast through the gap between Trinidad and Grenada. Turbulence can cause weird surface effects.

__________________
Hud
Hud3 is offline   Reply With Quote
Old 19-08-2013, 06:58   #4
Freelance Delivery Skipper..
 
boatman61's Avatar

Community Sponsor
Cruisers Forum Supporter

Join Date: Jan 2010
Location: UK/Portugal
Posts: 20,188
Images: 2
Send a message via Skype™ to boatman61
pirate Re: Wierd sea state - perhaps Internal Waves?

Often see the 'rivers' on ocean crossings... other strange phenomena as well... regular swell and wind F3-4 I've hit a 15 miles patch of 1ft high vertical waves... like someone had put a giant washing machine on spin cycle somewhere below... 4hrs later we were back in normal sea again.
Best was just W of the Galapagos Islands where I crossed a line of definite N-S current stretching as far as the eye could see in both directions... and the 'kick' as we crossed the line was quite noticeable...
__________________


Born To Be Wild
boatman61 is offline   Reply With Quote
Old 19-08-2013, 07:06   #5
Long Range Cruiser
 
MarkJ's Avatar

Cruisers Forum Supporter

Join Date: Dec 2007
Location: Australian living on "Sea Life" currently in England.
Boat: Beneteau 393 "Sea Life"
Posts: 12,828
Images: 25
Re: Wierd sea state - perhaps Internal Waves?

Tat current is certainly doing something!
It could be an eddy so the fast current between Trinidad and Grenada is turned and put back into the wind... thus getting those white caps.

What happend to your boat speed/heading when you crossed?
__________________
Notes on a Circumnavigation.
OurLifeAtSea.com

Somalia Pirates and our Convoy
MarkJ is offline   Reply With Quote
Old 19-08-2013, 07:48   #6
Senior Cruiser

Cruisers Forum Supporter

Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 17,314
Re: Wierd sea state - perhaps Internal Waves?

Either an eddy or an upwelling. We have seen dramatic upwelling some 100 miles West from Galapados. Now you think so far offshore the ocean should be more uniform. Well, it was not!

BTW - GREAT image, I always have problem photographing such events.

THX for sharing.

barnakiel
__________________
barnakiel is offline   Reply With Quote
Old 19-08-2013, 08:42   #7
Registered User

Join Date: Aug 2011
Location: Melbourne Australia
Boat: Paper Tiger 14 foot, Gemini 105MC 34 foot Catamaran Hull no 825
Posts: 1,616
Re: Wierd sea state - perhaps Internal Waves?

Big ocean currents crossing the Pacific, Coral sea and Tasman sea, There are quite a few of them,

About 5 miles wide, Like a big washing machine, Very Choppy, Irrespective of the oceans rollers, Very strong running current, around 4 knots,
I have maps of the Bottom, The currents are very strong and wild and weird when the Ocean floor depth changes, Long lines on the ocean floor that go for thousands of miles,
It spits up waves to about 30 feet high above what ever sea is running, and about 200 feet long, Then they just drop down and disappear,
They have nothing to do with the natural flow of the ocean waves, Possibly what is called a rogue wave,
__________________
Mr B is offline   Reply With Quote
Old 19-08-2013, 10:01   #8
Wayfaring Mariner
 
captain58sailin's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Homer, AK is my home port
Boat: Skookum 53'
Posts: 4,045
Images: 5
Re: Wierd sea state - perhaps Internal Waves?

It looks like a rip tide to me. They call it Soliton in Africa.
__________________
" Wisdom; is your reward for surviving your mistakes"
captain58sailin is offline   Reply With Quote
Old 19-08-2013, 10:06   #9
Registered User
 
Zanshin's Avatar

Join Date: Feb 2007
Location: Caribbean
Boat: Jeanneau 57
Posts: 1,621
Re: Wierd sea state - perhaps Internal Waves?

Curious indeed. How deep was the water? Were you off soundings or was it shallow?
__________________
-Zanshin (SV Zanshin)
Zanshin is offline   Reply With Quote
Old 19-08-2013, 10:19   #10
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 19,334
Re: Wierd sea state - perhaps Internal Waves?

That type of thing is so common up here in the PNW I guess we dont think about it much. Rops, tidal interfaces even standing overfalls of 4 ft or so!
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 19-08-2013, 13:50   #11
Armchair Bucketeer
 
David_Old_Jersey's Avatar

Join Date: Oct 2006
Posts: 10,013
Images: 4
Re: Wierd sea state - perhaps Internal Waves?

Quote:
Originally Posted by Cheechako View Post
That type of thing is so common up here in the PNW I guess we dont think about it much. Rops, tidal interfaces even standing overfalls of 4 ft or so!
Overfalls (even the flattish ones) always give me the heeby jeebies when going over them.
David_Old_Jersey is offline   Reply With Quote
Old 19-08-2013, 13:54   #12
cruiser

Join Date: Aug 2011
Location: Tampa Bay area
Boat: Hunter 31'
Posts: 5,731
Re: Wierd sea state - perhaps Internal Waves?

Quote:
Originally Posted by Hud3 View Post
The Antilles Current is pretty fast through the gap between Trinidad and Grenada. Turbulence can cause weird surface effects.


This place never stops amazing me.

I don't want to throw stuff in the water to look at currents. would it work to throw something off the bow that's tied on to the boat (floating line of course) so you could see how it tracks without littering?
__________________
Rakuflames is offline   Reply With Quote
Old 19-08-2013, 13:55   #13
Moderator
 
JPA Cate's Avatar

Join Date: Nov 2011
Location: aboard, cruising in Australia
Boat: Sayer 46' Solent rig sloop
Posts: 10,657
Re: Wierd sea state - perhaps Internal Waves?

Poiu,

Well done, sir. Most interesting post. FWIW, I think you got it right.

Ann
__________________
Ann, with Jim, aboard US s/v Insatiable II, in Oz, very long term cruisers
JPA Cate is offline   Reply With Quote
Old 19-08-2013, 14:07   #14
Registered User
 
Wrong's Avatar

Join Date: Jul 2013
Posts: 1,702
Re: Wierd sea state - perhaps Internal Waves?

Quote:
Originally Posted by Cheechako View Post
That type of thing is so common up here in the PNW I guess we dont think about it much. Rops, tidal interfaces even standing overfalls of 4 ft or so!
You ever anchor at Cypress Island, Pelican Harbour near Pelican Beach? The current really rips through there past Cone Island. As you say, common in the San Juans. Great place to learn to sail! Encounter just about everything there you'll encounter 'out there' at one time or another.
__________________
Wrong is offline   Reply With Quote
Old 19-08-2013, 14:40   #15
Registered User

Join Date: Nov 2011
Location: Montegut LA.
Boat: Now we need to get her to Louisiana !! she's ours
Posts: 3,421
Re: Wierd sea state - perhaps Internal Waves?

Hope yall had some fishin gear in the water!! Cus lots of times those rips are full of feedin fish !! Just a thought from an old fisher man !
__________________

__________________
Bob and Connie
bobconnie is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 03:20.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.