National Oceanographic Data Center 
National Oceanic and Atmospheric Administration 
US Department of Commerce 
2001 Wisconsin Ave., NW 
Washington, DC 20235 
(202) 634-7500 
Kind of Data 
Surface Current Data System (SCUDS) 
Location and Dates: Worldwide; dates of data vary from 
1850-present 
Description of Data: This data file contains over 4 million current set 
(direction) and drift (speed) observations made by seamen of The Netherlands, 
Japan, Great Britain, France, and the United States. Surface currents cal- 
culated from ship drifts are sometimes supplemented by Geomagnetic Eletro- 
kinetograph (an instrument which measures currents) observations. Data for 
the 19th century were collected primarily by The Netherlands; those of the 
1960s to present are primarily from US collections. 
The basic SCUDS file is organized geographically following National 
Oceanographic Data Center's (NODC's) Modified Canadian Consecutive Ten Degree 
square system which divides the world into squares for each 10 deg of latitude 
and longitude. The file is further broken into Il-deg squares within the 
10-deg squares and arranged by months and by years for each month. 
Most SCUDS records in the file contain the identity of its 10-deg, 5-deg, 
2-deg, l-deg, 1/4-deg and 1/10-deg square; the month; day and year; current 
direction and speed; and a data source code. 
In addition to current speed and direction, water temperature, wind direc-— 
tion and speed, sea direction and height, and swell direction and height are 
also included in the data file. The Netherlands' surface current data do not 
have wave information. 
Response Format: The basic outputs of the system are selected 
records and data summaries. These products are 
retrievable for a variety of geographic areas 
and time periods. Summaries are available in a 
long and short formats. The long format pro- 
vides area and time (monthly or period) iden- 
tity, basic statistical computations (area 
result direction and speed, north and east com- 
ponents, etc.), and a matrix of current speed 
and direction classes. Percent of observations 
for each direction and speed class, mean speed, 
maximum speed (per direction), and standard 
deviation are also included. The short summary 
format omits the matrix of direction and speed 
classes, but contains the area and month iden- 
tity, the average northern and eastern current 
vector components for the area, the resultant 
direction and speed, the total observation for 
IV-15 
