Ferry Glide Course
Calculate the heading to steer so cross current lets the boat ferry glide onto the desired course, correcting by the arcsine of the current to boat speed ratio signed by the side the current comes from.
Description
Calculate the heading to steer so cross current lets the boat ferry glide onto the desired course, correcting by the arcsine of the current to boat speed ratio signed by the side the current comes from.
Ferry Glide Course: Calculate the heading to steer so cross current lets the boat ferry glide onto the desired course, correcting by the arcsine of the current to boat speed ratio signed by the side the current comes from.
When to use Ferry Glide Course
Use this sailing calculation as a planning or educational cross-check for navigation, wind and current, rig loads, stability, anchoring, tides, visibility, performance, or recovery under explicitly stated conditions.
- Desired course (°)
- Track over ground wanted once across.
- Boat speed (kt)
- Boat speed through the water.
- Current (kt)
- Current strength acting on the crossing.
- Current side
- Side the current flows from relative to the desired course.
How Ferry Glide Course works
Calculate the heading to steer so cross current lets the boat ferry glide onto the desired course, correcting by the arcsine of the current to boat speed ratio signed by the side the current comes from. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.1
- Ferry glide course (°)
- Heading through the water that ferries onto the course.
Limitations and assumptions
- Actual conditions change with vessel design and loading, sea state, wind, current, tide datum, weather, chart accuracy, equipment, crew, regulations, and safety margins. Simplified formulas do not replace seamanship, approved stability data, or current navigation information.
- Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.
Alternative or Complementary approaches
Cross-check official charts, tide and weather services, instrument data, vessel manuals, and collision regulations; maintain conservative margins and a safe alternative plan.
References
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Navigation — Wikipedia contributors
Similar or alternative tools
- Lee Bow Effect Calculator
Project current onto the desired course as current speed times the cosine of the relative angle. This along-course proxy does not model the true lee-bow effect, which also depends on heading, boat speed, and apparent wind.
- Course to Steer With Current Calculator
Compute the heading to steer that compensates for a known tidal stream to achieve a desired track.
- Cross Track Error Calculator
Calculate the signed perpendicular distance from a desired course given distance run and the bearing back to the start point.