What is the course to steer between Port Jefferson Approach buoy "PJ" and New Haven Lighted Buoy "NH"? Your engine speed is 12 knots and you allow for a current of 93°T at 0.8 knot. A NW'ly wind causes 3° leeway.
• Plot the true course between Port Jefferson Approach buoy "PJ" and New Haven Lighted Buoy "NH" on the chart before applying any corrections. • Understand how to construct a current triangle using DR (dead reckoning) speed, set and drift of current, and course to steer. • Apply leeway from a NW wind correctly: decide whether to add or subtract the leeway angle from your water track heading.
• First, what is the true course (no wind, no current) between PJ and NH taken directly from the chart? That becomes the base of your solution. • Given an engine speed of 12 knots and a current of 0.8 knot set 093°T, how will this current push your vessel off the intended track? Sketch the velocity triangle and see which way the current vector points relative to your desired track. • A NW wind causes 3° leeway. In this situation, will the vessel be blown to the right or left of its track, and therefore should the heading be adjusted to the right or left to compensate?
• Make sure you are using true bearings throughout (no magnetic/compass conversion for this question). • Confirm the direction of set (093°T) and ensure your current vector points the correct way on the chart or velocity diagram. • After applying current and leeway, check that your resulting course made good actually lies along the straight line between PJ and NH. If it doesn’t, re-check your vector directions.
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