This page was last updated on 22 August 2015

Click here to 
Print this page

Biography finder

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

R

S

T

U

V

W

X

Y

Z

 

 

Index of first names

Douglas Sea Scale

 

 

 

 

 

 

The Douglas Sea Scale is a scale which measures the height of the waves and also measures the swell of the sea. The scale is very simple to follow and is expressed in one of 10 degrees.

The Douglas Sea Scale, also called the International Sea and Swell Scale, was devised in the 1920s by Captain H.P. Douglas, who later became Vice Admiral Sir Percy Douglas and Hydrographer of the Royal Navy. Its purpose is to estimate the roughness of the sea for navigation. The scale has two codes: one code is for estimating the sea state, the other code is for describing the swell of the sea.



State of the sea (wind sea)
Degree Height (m) Description
0 no wave Calm (Glassy)
1 0 - 0.10 Calm (Rippled)
2 0.10 - 0.50 Smooth
3 0.50 - 1.25 Slight
4 1.25 - 2.50 Moderate
5 2.50 - 4.00 Rough
6 4.00 - 6.00 Very Rough
7 6.00 - 9.00 High
8 9.00 - 14.00 Very High
9 14.00+ Phenomenal
Swell
Degrees Description
0 No Swell
1 Very Low (short and low wave)
2 Low (long and low wave)
3 Light (short and moderate wave)
4 Moderate (average and moderate wave)
5 Moderate rough (long and moderate wave)
6 Rough (short and heavy wave)
7 High (average and heavy wave)
8 Very high (long and heavy wave)
9 Confused (wavelength and height indefinable)


 

See also:

  • Douglas-Appleyard Arcless Sextant
  • Douglas navigation protractor

     

     

    Any contributions will be gratefully accepted



     

     

    Errors and Omissions

    The Forum

    What's new?

    We are looking for your help to improve the accuracy of The Douglas Archives.

    If you spot errors, or omissions, then please do let us know

    Contributions

    Many articles could benefit from re-writing. Can you help?


     

    If you have met a brick wall with your research, then posting a notice in the Douglas Archives Forum may be the answer. Or, it may help you find the answer!

    You may also be able to help others answer their queries.

    Visit the Douglas Archives Forum.

     

    We try to keep everyone up to date with new entries, via our What's New section on the home page.

    We also use the Community Network to keep researchers abreast of developments in the Douglas Archives.

     
     
     


  • Back to top

    The content of this website is a collection of materials gathered from a variety of sources, some of it unedited.

    The webmaster does not intend to claim authorship, but gives credit to the originators for their work.

    As work progresses, some of the content may be re-written and presented in a unique format, to which we would then be able to claim ownership.

    Discussion and contributions from those more knowledgeable is welcome.

    Contact Us

    Last modified: Saturday, 18 March 2017