This report is a summary of observations and collections 
made by P.O.B.S.P. personnel in the eastern Pacific Ocean from 
18-25 April, 1967. Participating personnel included Brian Harrington 
voiologrst-in-charge), Richard Heiden, and James Lewis. Superior 
cooperation was received from the officers and crew of the U.S.N.S. 
SHEARWATER(T-AG 177). The grid track was followed as accurately 
as circumstances would allow, but due to mechanical failures of the 
ship was not completed. On 22 April deviations from the nominal 
i I k 
cruise track were made between points E and t in order to mate 
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temporary engine repairs. Instead of continuing west, an, east 
course was taken from 0940 until 1330; at 1330 the course was 
once again reversed. Thus, a twenty mile portion of the track for 
the day was traveled three times. Observations over this transect 
will be discussed in the grid section of this report. Because of 
further problems with the main engine, none of the grid track between 
poinxs H and 0 was surveyed. Instead a direct course to Long Beach 
was taken from point H.. 
All positions on this cruise are considered accurate within 
live miles. Combined LORAN, sunlines and celestial fixes were taken 
hourly throughout the grid during diurnal hours; at night only LORAN 
was used. 
This report is divided into two sections. The first deals 
with the grid portion of the cruise while the second covers the non¬ 
grid survey. 
EASTERN PACIFIC GRID SURVEY 
'NUMBER 6 " 
The eastern grid survey was conducted from 1240 hours 19 April 
through 2400 hours 24 April, 1967, Only about two thirds of the 
