Operation Manual
110
111
Inner Ring 
On the inner ring, “MPH” (mile per hour) refers to “speed in-
dex”. This index is used to calculate the speed involving any 
data per hour. On the inner ring, “STAT” (statute miles) and 
“NAUT” (nautical miles) are for conversion of distance units.
OUTER RING
INNER RING
The following examples serve as a guide of how to use 
the slide rule.
SPEED CALCULATION: 
What speed is required to go 10 nautical miles in 
15 minutes? 
Known Factors: Distance: 10 nautical miles Time: 
15 minutes
•  Align “10” arrow on the outer ring with “15” on the 
inner ring.
•  The speed required can be found directly above the 
“MPH” marking on the inner ring.
The answer: 40 nautical miles per hour 
Time Calculation: How long will it take to go 10 nauti-
cal miles at a speed of 40 miles per hour? 










