Figure 22. Computer aboard USC&GSS Oceanog- 
rapher is used for data collection and processing. 
(ESSA photo) 
of the oceans prepared to various scales and 
various contour intervals and (2) studies of the sea 
floor to determine provinces of similar structures 
such as basins, ridges, and rises and to determine 
direction and degree of slopes. 
Location and description of submarine physio- 
graphic features are indispensable to: 
—Determining areas of potential mineral or petro- 
leum deposits. 
—Site selection for bottom installations. 
—Surface or subsurface navigation. 
—Developing sonar techniques for finding new 
fisheries. 
b. Future Needs There have been few major 
developments in bathymetric survey techniques 
and systems since invention of the sonic echo 
sounder and graphic recorder, although progress 
has been made in precision depth recorders and 
side-looking sonars. 
One major step, digital recording of soundings 
as a supplement to graphic recording, has cut 
drastically the time required to produce bathy- 
metric charts. This development can be improved 
even further. Faster and more detailed bathymet- 
ric surveying methods based on advances in acous- 
tic, photographic, recording, and other types of 
instrumentation are needed. 
Research into the seafloors changing topo- 
graphy and structure also is necessary for both 
military and nonmilitary use. Development of free, 
self-propelled, unmanned undersea probes as well 
as manned exploration submersibles will enhance 
survey capabilities. Such systems must operate to 
depths of 20,000 feet. 
The Navy Shipboard Survey Development Pro- 
gram includes capabilities to take narrow beam 
and wide beam bathymetric data from a cable 
towed instrument package operable to 20,000 
feet. The system includes devices to display 
essential data on a ship’s bridge. The Navy plans 
such capability for 11 vessels, 2 of which are now 
in operation, U.S.N.S. Silas Bent and U.S.N.S. 
Elisha Kane. 
2. Bottom Composition and Engineering Prop- 
erties 
a. Current Situation Knowledge of the composi- 
tion, properties, and mechanical behavior of sea- 
floor sediments is essential for designing founda- 
tions, recovering minerals, predicting the behavior 
of vehicles and equipment on or in the ocean 
floor, tunneling, pipeline and cable laying, control- 
ling pollution, disposing of waste, salvaging and 
recovering objects, and interpreting geophysical 
records. In underwater work, soil mechanics must 
be applied in drilling, coring, pile driving, dredging, 
mining, and operations involving penetration into 
seafloor sediments. 
Soil mechanics is established reasonably well 
for engineering tasks on land. With very few 
exceptions, theoretical and applied ocean soil 
mechanics (away from coastal areas) is no more 
than 15 years old. The studies and measurements 
made in this relatively short time are few. High 
pressures, dynamic conditions, and inaccessibility 
contribute to the complexity of the problem. 
The reliability of underwater soil engineering 
data must be better than for land applications. 
Failures of land structures due to erroneous soils 
data can be remedied and normally are not 
catastrophic. Submerged installations, however, 
are not susceptible to convenient repairs; failures 
can be costly and hazardous. 
Remote sediment sampling from surface ships 
by snappers, dredges, and corers is unsuitable to 
obtain the relatively undisturbed samples needed 
for engineering purposes. /n situ sediment sam- 
V1-63 
