Reconnaissance by Submarine — B rock and Chamberlain 
379 
met with failure. In each case the ship had to be 
backed to recover the dredges and the cutting 
edge of the dredge was frequently bent. 
Trawling 
A standard shrimp try trawl was tested as a 
collecting device in the general area of the 
"Asherah” operations, but deeper and south of 
the area off Pokai Bay. The trawl was hauled 
twice in about 350 meters of water and took a 
scant catch with a good deal of damage to the 
net. The echo sounding record had indicated a 
smooth bottom. The tension on the cable 
reached one ton, overloading the ship’s genera- 
tor. A new net was rigged and shot in a sand 
channel off Pokai Bay which was presumed to be 
free of obstructions. The gear was towed per- 
pendicularly to the trend of the coast offshore 
beginning in 20 meters of water and ending in 
about twice that depth. A large catch was taken 
of nearshore fishes, including a female Dasyatis 
hawaiiensis whose weight must have exceeded 
100 kilograms even though the fishing time 
was quite short. Again the net was badly 
damaged. 
Both the dredging and trawling operations 
indicated that the "Teritu” was quite inadequate 
for this use. 
MARINE GEOLOGY 
Geomorphology 
The submarine geomorphology between 
Kaena and Kepuhi points, is dominated by a 
series of marine terraces separated by escarp- 
ments. From the "Asherah” it was possible to 
discern at least three distinct levels: 
(1) An upper level terminating seaward at 
a depth of approximately 60 meters. 
(2) An intermediate level extending from 
about 70 meters down to approximately 120 
meters. 
