Coastal Skipper and Yachtmaster Quiz · Chartwork and passage planning
On a 12-hour crossing the tide sets you east for six hours, then west for six. To work out one course to steer for the whole crossing, what tidal set do you allow for?
A bar chart of the cross tide for each hour of a 12-hour passage, in miles. Hours 1 to 6, tide setting east: 0.8, 1.6, 2.2, 2.2, 1.6, 0.6, labelled 9.0 M in all. Hours 7 to 12, tide setting west: 0.6, 1.4, 2.0, 2.0, 1.4, 0.6, labelled 8.0 M in all.
Show the answer
1 mile to the east. On a long cross-tide passage, add up the tide for the whole crossing and allow only for the net figure: 9.0 miles east less 8.0 miles west is 1.0 mile east. You steer one course and let the tide carry you off the line and back again, which is quicker than fighting it hour by hour. Check that the curved track over the ground stays clear of dangers.
