Old Weather Forum

At the present time, we are not transcribing figures in the State of the Sea column(s).

Philip Brohan, our chief climatologist, has explained that the state of the sea is not necessarily connected with the local weather.
Swells and currents in the ocean can be generated by storms that are literally thousands of miles away.
Wind driven surface waves may travel vast distances.


Mentions of state of the sea in Directions for keeping the ship's log:

• US Navy
  • 1882
    https://s3.amazonaws.com/NARAprodstorag ... 94_005.jpg
  • 1908
    https://s3.amazonaws.com/NARAprodstorag ... 5_0003.jpg
  • 1943
    https://s3.amazonaws.com/NARAprodstorag ... 9-0003.jpg
  • 1947
    https://s3.amazonaws.com/NARAprodstorag ... 3-0005.JPG
• US Revenue Cutter Service and US Coast Guard
  • 1913
    https://s3.amazonaws.com/NARAprodstorag ... 08_004.jpg
  • 1921
    https://s3.amazonaws.com/NARAprodstorag ... 1-0004.JPG
  • 1930
    https://s3.amazonaws.com/NARAprodstorag ... 0_0004.JPG
  • 1950
    https://s3.amazonaws.com/NARAprodstorag ... 3_0004.JPG
• Royal Navy
  • 1906
    http://oldweather.s3.amazonaws.com/ADM% ... -005_0.jpg
  • 1914
    http://oldweather.s3.amazonaws.com/ADM5 ... -005_0.jpg
• Modern Sea Disturbance Scale

Other resources:

• National Oceanic and Atmospheric Administration
• NOAA Central Library
• NOAA Pacific Marine Environmental Laboratory
• National Geospatial-Intelligence Agency, Maritime Guidance (detailed seabed material codes)
• Seabed Symbols for Safer Sailing Navigation, Current
• Chart Legend (PDF)

H-039-2: Typhoon Cobra — The Worst Natural Disaster in U.S. Navy History

USS Langley (CVL-27) rolling sharply during extreme weather conditions in the Pacific,
likely Typhoon Cobra, 14–19 December 1944


H-039-3: Typhoon Cobra: A Personal Account

Destroyer during heavy weather in the East China Sea, possibly during Typhoon Cobra in December 1944.
Photographed from USS New Jersey (BB-62) (80-G-470284)




USS Cowpens (CVL-25), "The Mighty Moo," starboard side flight deck facing aft from the island.
Photo was taken around the time Typhoon Cobra hit the Third Fleet on 18 December 1944.
https://laststandonzombieisland.com/201 ... ago-today/



Gordon Smith posted http://www.naval-history.net/IndexVideo ... matsea.wmv
He commented that this helps to understand how even the biggest of ships get damaged and even disappear.
It was sent to him by an ex-RN Commander in Australia.

OW glossary

With a strong wind and a big sea running, even quite big ships will prefer to steam into the wind, rather than take the force of wind and wave on the side or stern of the vessel.

When the vessel is turned head to wind the object is to make very little progress over the ground, just enough to keep the vessel steering and the engine speed will be adjusted accordingly. You'll see this referred to as "hove to" in the logs sometimes, a relic of sailing ship days when the main yard was hove round to the wind to stop the ship temporarily, to speak to another vessel or the like.

Of course sailing ships couldn't adopt the steamers' tactic of heading into the wind and wave and faced with a very strong blow would be obliged to put before the wind with as little sail as possible, dangerous but their safest course. Some sailing ships also do well "lying a-try", taking all sail off and allowing the ship to adapt to the weather by herself.
[dorbel]

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You will also find a few river-related terms here.


Chow chow:
Rippling and and swirling water. This seems to apply to rivers rather than the sea. https://books.google.com/books?id=wf0NA ... navlinks_s


Confused sea:
Waves of irregular heights, wavelengths and direction. Occasionally observed after seismic disturbance but more often caused by a conflict of wind, tide and/or current in relatively shallow water. Deeply annoying to yachtsmen, shouldn't bother a ship much unless they are very severe. [dorbel]
+

Aerial photograph of confused sea state from cockpit of Coast Guard aircraft en route to the Bahamas during the Hurricane Dorian response effort. (U.S. Coast Guard photo by Petty Officer 2nd Class Cody Dickey)


Density
http://www.ric.edu/faculty/PSCI103/Seaw ... _notes.htm [Dean]
+
Density (weight per unit volume) can also be expressed as specific gravity (the ratio of the weight of a substance to the weight of an equal volume of fresh water). The average for sea water in the open ocean is 1.025. (So sea water is 2.5% heavier than fresh water.) This is the number sailors use for calculating the draft of the their ship. Some sources use 1.026 or even 1.027.
In polar waters, because of the proximity of melting ice, the surface density can change over short distances because the fresh water may float on the surface for a time before mixing into the sea water.
Sailors want to know the density of the water because their ship will float 2.5% lower in fresh water, because it is less dense. This will make the draft readings deeper, so because of legally required maximum drafts, you have to know what the density, or specific gravity, is of the water you are currently floating in. Also, it may make a difference for passing over certain shallow areas, especially sand bars at harbor entrances. [Jeff]
+
Oceanographers go to great care to accurately measure seawater density because it determines the structure and movement of water masses relative to each other in the ocean, especially once they get deeper than the wind does (top couple hundred meters or so.)
The interaction of temperature and salinity in high-latitude waters, influenced by freezing/melting, forms some incredibly dense seawater that sinks and circulates in the depths of worlds' oceans. The long-term changes in surface seawater density caused by changes in ice fields and seasonal freezing/thawing in polar waters as the atmosphere warms have the potential to influence both surface and deep water circulation. [camiller]


Flood tide:
Incoming tide; as opposed to ebb tide. [Bunting Tosser]


Following sea:
A "following sea" refers to a wave direction that is similar to the heading of a waterborne vessel under way.
https://en.wikipedia.org/wiki/Following_sea [ggordon]


Ground swell:
A sudden swell preceding a gale, which rises along shore, often in fine weather, and when the sea beyond it is calm. http://www.gutenberg.org/files/26000/26 ... 6000-h.htm
+
A broad deep undulation of the ocean, often caused by a distant storm or an earthquake. https://www.thefreedictionary.com/groundswell


Head sea:
Sea where waves are directly opposing the motion of the ship. https://en.wikipedia.org/wiki/Glossary_ ... al_terms#H
+
A name given to the waves when they oppose a ship's course, as the ship must rise over, or cut through each. Their effect depends upon their height, form, and speed; sometimes they are steep, quick, and irregular, so that a ship is caught by a second before she has recovered from the first; these render her wet and uneasy. http://www.gutenberg.org/files/26000/26 ... 6000-h.htm


Shoaling:
Shoaling can simply mean becoming shallow. https://www.thefreedictionary.com/shoaling
+
However it can also refer to effect that moving from deeper water to shallower water has on waves. In this case, shoaling is an increase in wave height that happens when waves go from deep to shallow water.
For a detailed explanation, see https://www.sciencelearn.org.nz/resourc ... i-shoaling


Water spout:
http://www.bbc.co.uk/news/world-asia-pacific-13593871

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Please post questions and suggestions for additions or changes in Weather, sea, and ice (past, present, or future -- on Earth or elsewhere): discussion.