Friday, January 20, 2017

two kinds of swells, de Gast



Outer Banks friend Jim B. tells me about a cool website with a fascinating visualization of ocean swells.  The website is from Ventusky which produces wind, rain and temperature maps.  From their press release the major improvement is showing both ocean swells and wind waves.  From the release....

"The application displays two types of waves: swells and wind waves. Waves travelling outside of their place of origin, and are thus not caused by local winds, are called swells. Waves caused by winds in that specific location are called wind waves. The total height of the wave is the combination of the height of the swells and the height of the wind wave. In the application, wind waves are marked in white and swells are marked in black."



In the screenshot above, showing a storm in the southern Atlantic, you can see the regularly existing ocean swells in black and the wind generated swells in white.  The image below shows the wind causing those waves.


Pretty interesting.  I doubt that this site will provide much information for my local sailings on Chesapeake Bay and down in North Carolina, but it will be interesting to watch as Webb begins rounding the bottom of Africa and making the 6,000 mile sail to St. Lucia.   I will be following Gannet's yellow brick track and it will be nice to get a very complete idea of wind, swells and waves that Webb will be experiencing.   Below you see Gannet hauled out for fresh antifouling paint.  She may be back in the water already as Webb provisions before for casting off on the next leg of his circumnavigation.


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I am so very glad to hear that the Chesapeake Bay Maritime Museum is putting together an exhibition of the work by sailor and Chesapeake Bay photographer Robert de Gast.  I've been a fan of his work for years, even tried to buy some of his books but they are all now considered collector's items.  The museum will show 80 of his images beginning May 12.  Read about the exhibition and the photographer here.

2 comments:

MaryLou said...

Really looking forward to the deGast exhibit. I've got a couple of his books - Western Wind, Eastern Shore, and Five Fair Rivers. Magical stuff - the writing and the photos.

Steve said...

Lucky you to have those books. They are hard to find these days.

steve