TR No, 22 
Measurements were made on 4 November 1966 from 1300 hours to 1400 
hours, The time of high tide at Newport was given as 1130 hours, and 
therefore measurements were made during the interval when the current 
was a maximum of 3.0 knots south. 
The width of the channel at Station I is approximately 116 meters, 
and the depth 6.7 meters, North of Station I the depth is 18.6 meters, 
and in the area from Station I to Station II, 800 meters south of I, the 
depth varies from around 10 to 20 meters, with a width of about 400 meters. 
The Reynolds number based on width at Station I is approximately 1.3 x 108, 
Figures 9, 10, and 11 show the method of mounting the current meter 
on the bow of the NUWS boat, a 74-foot OAL torpedo retreiver. Brackets were 
fabricated to support the mount ing strut, an 11 1/2-ft long section of 
steel pipe approximately 1 1/2" in diameter, to the lower end of which was 
clamped a 3-ft length of 3/16-in by 3-in steel bar stock, along the bow. 
When in position the lower end of the strut extended approximately 1 1/2 
meters below the surface of the water. The current meter was affixed to the 
end of the strut in a horizontal position; the clamping arrangement allowed 
the bar stock to be rotated so that the axis of the current meter could be 
aligned with the centerline of the boat. 
The current meter output was recorded on FM magnetic tape at 30 inches/ 
Sec on a Precision Instrument PI-2100 recorder, It was necessary to include 
an attenuator in the circuit to reduce the signal level 8 dB to an appropriate 
level for the recorder, A gasoline engine driven 115 VAC generator followed 
by a Sorensen voltage regulator was used to supply power to the recorder. 
The original intention was to proceed against the current from Station II 
to Station I along the centerline of the channel at as slow a velocity as pos- 
sible in order to obtain the maximum amount of data with a minimum change in 
position or downstream distance from the channel buoys, The ideal technique 
would have been to tow the instrument at a velocity equal to that of the cur- 
rent. The first run showed that this was impracticable as it was impossible 
to control the boat in the turbulence at such low velocities, The remaining 
runs were made at a velocity of 4 meters-sec”+ relative to the water; the 
engine RPM was maintained constant throughout. A typical run consisted of 
dial 
