ASA 105: Skill 12, Estimated Position (EP)
12: Allow for the effect of current and leeway to plot the estimated position. Estimated Position or EP is DR plus outside influences factored into the outcome. Outside influences are current, steering error, and/or leeway to name the most common. Continuing with the earlier example, factor in the current. Using Eldridge, for example, we determine that a fair current occurs for our trip when we are in Buzzards Bay at the time Ebb Starts at Pollock Rip Channel. See page 78. We plan to arrive at Cleveland Ledge Light in time for the Ebb at Pollock Rip to start. Assume we depart the Cleveland Ledge Light on 17 July 2022 at 1230. See page 69. We carry a fair current of about 1/2 knot down the Bay. Turning into Quick's Hole we face a head current of 2 1/2 knots for the short distance. Crossing to Menemsha Harbor the current is on the beam at about 1 knot. Leg Base speed Corrected speed Corrected transit 1 6 6.5 1h 52m 2 6 3.5...