a4 
The line spacing for surveys of this nature will be determined 
on the basis of the data already available from the area, the 
desired intensity of coverage for various types of data, the 
environmental complexity of the area, the adequacy of avail- 
able navigational control, and such other factors as distance 
of the area from the operating bases of the ships, expected 
weather and sea conditions, and the availability of equipment 
to make all the basic underway measurements listed above. 
Oceanographic station observations, on the other hand, 
are those in which the ship is required to stop in order to 
make the observations. As in the underway operations, the 
spacing of observations will vary with the area under investi- 
gation. Oceanographic station observations will ideally 
include measurement and sampling of the physical, chemical, 
biological, and geological properties of the entire water 
column and the ocean floor and measurement of the meteorolog- 
ical characteristics of the overlying atmosphere. 
In the early stages of Ocean Surveys, both underway 
operations and oceanographic station operations were carried 
out from the same ship but at different times during the field 
season. As the Ocean Surveys progress, it will probably be 
found expedient to have some ships carry out underway opera- 
tions as their primary task, while other ships will be 
assigned primary responsibility for oceanographic station 
operations. The division of ship tasks is one facet of the 
Ocean Survey Plan to which operational analysis will be 
directed. 
