At 0829 your position is LAT 41°02.9'N, LONG 72°57.4'W. You are making turns for 8.5 knots. What is your ETA at a position midway between buoys "1" and "2" at the entrance of New Haven Outer Channel?
• Speed-Time-Distance relationship for ETA problems • Converting minutes and seconds of latitude/longitude into decimal minutes to measure distance on the chart • Using the chart scale: 1 minute of latitude = 1 nautical mile
• From your 0829 position, how will you determine the distance in nautical miles to the midpoint between buoys 1 and 2 ? Think about what you would physically measure on the chart. • Once you have the distance, how do you convert that distance and your speed of 8.5 knots into time underway? What formula connects these pieces? • After you get the steaming time in hours and minutes, how do you add that correctly to 0829 to check which ETA choice matches best?
• Be sure you are measuring to the midpoint between buoys 1 and 2, not to one buoy or the other. • Confirm you converted your distance and speed consistently in nautical miles and knots (nm/hr). • Double-check your time addition from 0829 (watch out for rounding and converting decimal hours into minutes).
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