You are on a voyage from Baltimore, MD to Seattle, WA. The distance from pilot to pilot is 5960 miles. The speed of advance is 16.0 knots. You estimate 16 hours for bunkering at Colon, and 12.0 hours for the Panama Canal transit. If you take departure at 0824 hours (ZD +5), 18 November, what is your ETA (ZD +8) at Seattle?
• Speed = Distance / Time relationship and how to rearrange it to find time of voyage • How to convert total travel time in hours into days and hours, then apply it to a calendar date • How to convert between time zones using Zone Descriptions (ZD), especially from ZD +5 at departure to ZD +8 at arrival
• First, ignore bunkering and canal time. Use the distance and speed of advance to compute the pure steaming time in hours, then add the bunkering and canal delays to get a total elapsed time. • Once you have the total elapsed time in hours, carefully convert it to days and leftover hours. Then add that to the departure local time and date (ZD +5) to find the arrival time in that same ZD. • Finally, convert that arrival time from ZD +5 to ZD +8 by applying the correct sign and number of hours, watching carefully for any date change when you shift time zones.
• Verify you used Speed (knots) = Distance (NM) / Time (hours) correctly and solved for Time. • Check your arithmetic for converting hours to days plus hours, and for adding days across from November into December. • Confirm that the time zone conversion from ZD +5 to ZD +8 is in the correct direction (are you adding or subtracting hours?), and adjust the date if the clock crosses midnight.
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