Reconnaissance by Submarine — Brock and Chamberlain 
375 
Fig. 2. View from above Kaena Point. The seafloor is delineated from the water’s edge to and beyond the 
escarpment between the Mamala and Lualualei terraces. Sand channels and reef rock outcrops are shown. 
(Drawing by Ken Shutt.) 
it contained numerous, well developed sub- 
marine terraces and escarpments that could be 
correlated with ancient stands of the sea, as 
recorded in recent borings made on the Ewa 
Plain 20 miles to the south. 
ENVIRONMENTS 
Oceanographic 
SURFACE CURRENTS: The Hawaiian Islands 
are located on the northern edge of the Pacific 
North Equatorial Current, a westerly-flowing 
component of the large anticyclonic circulatory 
pattern that dominates the North Pacific Ocean. 
Within a few hundred miles of the Hawaiian 
Islands the surface currents all set toward the 
western quadrant, generally with a drift of 
about l/ 2 knot. As this large mass of water 
flows past the Hawaiian Islands it breaks up on 
the downstream side of the islands into large, 
semi-permanent eddies, some cyclonic and others 
anticyclonic. Superimposed upon these eddies, 
and in some cases completely dominating the 
surface circulations, are strong tidal currents. 
About 10 miles off western Oahu the surface 
water appears to consistently move south, in 
conformation with the general flow of water 
from the east through the Kauai Channel, and 
join the circulation of an anticyclonic eddy 
about 20 miles in diameter located about 20 
miles directly offshore at southwest Oahu 
(Latham, 1967). The velocity of the near-Oahu 
portion of this eddy was measured by Latham 
and found to be about l/ 2 knot to the south. 
Nearer shore the surface currents have been 
found to reverse themselves semi-diurnally in 
accordance with the tides. During flood tides 
there is generally a flow of water to the south 
just west of Kaena Point, and to the southeast, 
south of the point. These currents have been 
measured at about ll/ 2 knots (Latham, 1967). 
However, immediately adjacent to the coast, 
both north and south of Kaena Point, there is 
a persistent drift of water of 1-2 knots that 
follows the coastline to a convergence point 
some few miles west of Kaena Point. These 
northwest-setting currents are more intense 
during ebb tide and have been measured at a 
maximum of 5 knots (Laevastu et al., 1964). 
During the diving operations with the 
"Asherah” a nearly constant set to the north and 
west was encountered. The drift of this cur- 
rent varied, but l/ 2 knot was not uncommon 
even to depths of 180 meters. 
waves: Wave energy reaching the western 
coast of Oahu can be approximately represented 
by four wave types related to predominant 
