Boat Navigation Math: Speed–Time–Distance, Set & Drift, Fuel Range & Anchoring

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Turn the waypoint latitudes of a fictional coastal trip from degrees and minutes into decimal degrees, measure a north–south distance in nautical miles, convert speeds into knots and write a GPS reading back in degrees and minutes for the log.
• Work out the time for every leg of Gullwing's passage, the arrival time at each waypoint, the true average speed of the whole passage and the latest departure that still reaches the visitors' pontoon before it closes.
• Split every leg of the passage into a north and an east component in nautical miles, correct the east component for the latitude, add up the passage distance with Pythagoras and turn the components into a true course with ATAN2.
• Add the boat's motion through the water and the current as north and east components, find where Gullwing really goes over the ground, then work out the course to steer that cancels the current and the leg time that results.
• Read speed and fuel burn for each leg's engine setting from a fictional engine table, total the fuel for the passage, find the most economical engine speed and check how much fuel is left above the school's reserve at arrival.
• Compare five fictional anchorages: look up the scope for the rode type, work out how much rode to let out to the next mark, check the swing circle against the room to the nearest hazard and count the anchorages that work.
• Turn charted depths and bridge clearances into the real values at your ETA, check them against Gullwing's draft and air draft with the school's margins, flag every spot as Go or Wait and colour the shallow spots that fail.
• Bring the course together on one passage plan: leg times from the expected speed over ground, ETAs, fuel on board after every leg, three checks against the school's rules, a single GO / NO GO decision and a chart of the fuel running down.