The Australian Coastal Navigation Handbook

Plot the following positions accurately on your Hypothetical Bay chart:

• a) 23° 53.0' S, 161° 58.0' E
• b) 24° 01.2' S, 162° 03.8' E
• c) 23° 56.3' S, 162° 06.5' E

Find and record the latitude and longitude of the following features on your Hypothetical Bay chart. Give your answers to the nearest 0.1 minute. Remember: latitude first, then longitude, with hemisphere indicators (S and E).

• a) The Fairway Beacon
• b) Reid Light
• c) Pamela's Light

Using dividers and the latitude scale on your chart, measure the distance between the following pairs of features. Give answers in nautical miles to one decimal place. If the distance is greater than your divider span, use the walking technique.

• a) The Fairway Beacon to Trent's Light
• b) Reid Light to Pamela's Light
• c) Gregory Light to Hamlyn Light

Remember: Always use the latitude scale on the side of the chart. Never use the longitude scale for measuring distance!

Complete the following calculations, showing your working. Try each one on paper before revealing the answer.

Part A: You need to cover 18 nautical miles in 3 hours. What minimum speed must you maintain?

Using any available chart (or Hypothetical Bay):

• a) Locate and record the chart number, publication date (or edition date), and Notice to Mariners reference.
• b) Identify the chart scale and state whether this chart is most suitable for: passage planning across open water, coastal navigation along a coastline, or pilotage into a harbour.
• c) If present, locate the survey reliability (ZOC) diagram and note which areas have the best survey coverage.

Learning objective: Finding and interpreting critical chart information before using it for navigation.

Using the Hypothetical Bay chart:

• a) Draw a line from The Fairway Beacon to Maclean Reef. Use your Portland plotter to measure the True bearing. Record as: _____°T
• b) Use dividers to measure the distance between these two points. Record as: _____ NM
• c) Draw a line from Trent's Light to Gregory Light. Measure the True bearing: _____°T and the distance: _____ NM
• d) If you depart The Fairway Beacon at 0900 and travel to Maclean Reef at 6 knots, calculate your ETA (show working).

On your chart (Hypothetical Bay or available chart):

• a) Find and identify three different types of aids to navigation (e.g. lighthouse, buoy, beacon, leading marks). Record the name/position and symbol type for each.
• b) Locate one danger or obstruction (e.g. wreck, rock, reef). Record what type of danger it is.
• c) Find one area showing the nature of the seabed. Record the bottom type (e.g. sand, mud, rock, coral).
• d) Identify one restricted or special area. Note what type of restriction applies.

Using an Autsralian chart:

• a) Locate and record what chart datum is used (e.g. LAT).
• b) Find a green-shaded drying area and record its drying height. If high tide adds 2.5 metres of water, what depth would you have over this area at high tide? If your boat draws 1.8 metres, would it be safe to cross at high tide (considering safety margin)?
• c) Identify and trace the 5-metre depth contour line in one area of the chart.
• d) Find three spot soundings and record their depths.
• e) Identify one area of blue shading (shallow water). What is the approximate depth range shown in blue on this chart?

Given:

• ◆ Chart course: 140°T
• ◆ Variation: 11°E (from chart)
• ◆ Deviation: 1°E (from deviation card)

Calculate the compass course to steer. Show all working with T, M, C labels.

Given:

• ◆ Compass bearing observed: 278°C
• ◆ Deviation: 2°W (from card for heading ~280°)
• ◆ Variation: 11°E (from chart)

Calculate the true bearing to plot on the chart. Show all working.

Use this deviation card for all three parts. Variation for all questions: 11°E

• a) Course 035°T, Variation 5°W  — What compass heading to steer?
• b) Course 180°T, Variation 11°E — What compass heading to steer?
• c) Observed bearing 090°C, Variation 8°E  — What true bearing to plot on the chart?

You plan a three-leg passage with these true courses. Using variation 11°E and the deviation card from Exercise 3, calculate the compass heading for each leg. Write out each conversion with all steps labelled.

• Leg 1: 045°T
• Leg 2: 180°T
• Leg 3: 310°T

A crew member gives you their conversion:

• a) Is this correct?
• b) If not, what's the error?
• c) What should the correct compass course be?

Using the Hypothetical Bay chart:

• a) Measure the true bearing from The Fairway Beacon to Maclean Reef using your Portland plotter.
• b) If variation is 8°E and deviation on that heading is 2°E — what is the magnetic bearing? What is the compass bearing?
• c) Now reverse it: if you observed a compass bearing of 180°C to Pamela's Light from your position, with deviation 2°W and variation 8°E — what true bearing would you plot on the chart?

Scenario: You take three compass bearings (magnetic). Variation is 8°E.

• ◆ Paula's Light: 335°M
• ◆ Trent's Light: 209°M
• ◆ Fairway Beacon: 288°M

Tasks:

• 1. Convert all three bearings to true.
• 2. Plot all three bearings on the chart.
• 3. Observe the cocked hat that forms.
• 4. Assess whether this is a good fix (small cocked hat) or poor fix (large cocked hat).
• 5. Consider: was the spread between objects good? Were they close or distant? Which would you take first? Last?

Scenario: You depart from the Fairway Beacon at 0900 hours. You steer a course of 045°T at 3 knots. After 1.5 hours (at 1030), you want to plot your DR position.

Tasks:

1. 1. Calculate the distance travelled (Distance = Speed × Time).
2. 2. Draw a line from Fairway Beacon on course 045°T.
3. Measure the distance along this line.
4. Mark your DR position with a semicircle and label with the time (1030).
5. Mark the track line with a single arrow showing direction.
6. What is your posiiton (latitude and longitude)?

Scenario: You depart from Maclean Reef at 1200 hours. You steer 270°T (due west) at 5 knots for 2 hours. During this time:

• ◆ Tidal current sets 000°T (due north) at 1.5 knots
• ◆ You estimate 5° of leeway to the south due to wind from the north

Tasks:

• 1. Plot your track, allowing for leeway.
• 2.  Plot your DR position (10 nm along your track).
• 3.From your DR position, plot the tidal effect (3 nm north over 2 hours). 
• 4. Mark your final EP and label.
• 5. Draw your ground track from start to EP.

Scenario: At 0800 you start out from Col's Reef. You sail on a broad reach on a heading of 090°T at 6 knots. At 0900 (after one hour), you can see only Reid Light. You take a bearing to Trent's Light: 288°M (variation 8°E).

Tasks:

• 1. Plot your 0800 fix position at Col's Reef.
• 2. Plot your 0900 DR position (6 nm east of Col's Reef).
• 3. Plot the bearing to Trent's Light (converted to true).
• 4. Does this bearing line pass close to your DR position?
• 5. If not, consider possible reasons (current? steering error? compass error?).
• 6. How confident are you in this position compared to a three-point fix?

Scenario: You are entering Jensen River from seaward. The channel is marked with lateral marks.

Tasks:

• 1. Trace the channel from the seaward entrance up Jensen River to the harbour.
• 2. For each lateral mark you encounter, note its colour (red or green), which side of your vessel it should be on (port or starboard), and its light characteristic (if shown).
• 3. Identify at least 3 port lateral marks and 3 starboard lateral marks.
• 4. Explain: if you were leaving this harbour and heading out to sea, how would the positions of red and green marks change relative to your vessel?

Scenario: On the Hypothetical Bay chart, locate the cardinal marks around various hazards and dangers.

Tasks:

• 1. Find one example of each type of cardinal mark: North, South, East, and West.
• 2. For each, draw or describe: the topmark (which way the two triangles point), the colour pattern (where black and yellow are positioned), and which side you should pass the mark on.
• 3. For the North cardinal you found: what danger is it marking? What would happen if you passed on the wrong (south) side?

Scenario: You encounter various marks while sailing. Identify each one from its description.

Scenario: You are approaching Heyer River on Hypothetical Bay at night from the southwest (sailing between Sumpter and Wiley Island). You need to plan your approach using buoys and lights.

Tasks:

• 1. Study the chart and identify: the sequence of lateral marks into the harbour, any cardinal marks warning of hazards, and lighthouses and characteristics.
• 2. Create a navigation plan listing each mark you expect to see in order, its colour and light characteristic, which side to pass it on, and approximate bearing and distance from the previous mark.
• 3. Draw your intended track on the chart showing your approach from seaward, the route through the marked channel, and which side of each mark you'll pass.

• a) If today is a full moon, are we experiencing spring or neap tides? What about one week after full moon?
• b) If high tide is at 0830 today, approximately what time will low tide be?
• c) What time will high tide be tomorrow?

Fort Denison shows:

• a) What is the tidal range?
• b) Is this closer to springs or neaps?

Hint: typical range at Fort Denison is 1.0–1.2m at neaps, 1.5–1.8m at springs.

Given:

What is the predicted height at 0900 — three hours after low water?

Scenario: A bar has 2.0 metres depth at chart datum. Your boat draws 2.2 metres. You want 0.8 metres under-keel margin, so you need a total of 3.0 metres of water.

When can you safely cross the bar? Calculate when the tide reaches the height you need.

Hint: 2.8m needed minus 2.5m charted = 0.3m tide height needed above chart datum.

Using a chart of your local cruising area:

• 1. Identify a 30–50 nm coastal passage.
• 2. Mark all hazards along the route — rocks, shoals, restricted areas, wrecks.
• 3. Identify and mark two safe harbours (bolt-holes) along the route.
• 4. Create waypoints that clear hazards with appropriate safety margins.
• 5. Draw your planned route connecting all waypoints.

Learning objective: Practise the full route selection and hazard identification process on a real chart.

Scenario: 25 nm passage. Your boat makes 6 knots. Your draft is 1.8m and you need 0.7m margin.

• a) Using the Rule of Twelfths, calculate when you can safely cross the bar outbound.
• b) Calculate the latest departure time to clear the bar.
• c) If tidal streams run favourable from 0800–1400 at 2 knots, what's your optimal departure time?

For a passage leg with the following parameters:

• ◆ True course measured on chart: 224°T
• ◆ Variation from chart: 11°E
• ◆ Deviation from boat's card at heading ~220°: 2°W

• a) Calculate the magnetic course.
• b) Calculate the compass course to steer.
• c) Show all working and conversions.

Create a complete passage plan document for a real or simulated passage. This is the exercise that pulls everything together — use either a passage you're planning to sail, or create one from your local chart.

Your plan should include:

• ◆ Vessel and crew details with emergency contacts
• ◆ Departure and destination information
• ◆ Complete waypoint table with courses, distances, and ETAs
• ◆ Weather forecast summary and tide information
• ◆ Emergency information and safe harbour alternates
• ◆ Fuel calculations and provisions list
• ◆ Communications plan

Use the passage plan template provided in the course materials, or create your own format ensuring all essential elements are included.

Using a chart of your local harbour or the Hypothetical Bay chart:

• 1. Identify the outer approach from seaward to the harbour entrance.
• 2. Mark all key features: buoys, lights, beacons, transits, headlands.
• 3. Identify hazards and note how you'll avoid them.
• 4. Annotate the chart with courses, distances, clearing bearings, and turn points.
• 5. Create a pilotage notebook page with step-by-step instructions you could hand to a helmsman.

Learning objective: Build a complete, usable pilotage plan from scratch — the kind you'd brief a crew on before entering harbour.

Using your chart:

• a) Identify three possible transits — pairs of objects that could align to define a track.
• b) For each transit, describe what objects form it and what track it defines.
• c) Select one hazard and calculate a clearing bearing that keeps you safe.
• d) Write the clearing bearing instruction in the standard format.

For your pilotage route, using variation 11°E and deviation 2°W:

• a) Identify two waypoints on your route that require course changes.
• b) For each, select a visible landmark and calculate a turn bearing in true.
• c) Convert each turn bearing to compass.
• d) Write complete turn instructions in the standard format.

Imagine you're approaching your harbour at night:

• a) List the lights you would see first, in order of appearance.
• b) How would you confirm you're on the correct approach bearing?
• c) What would you do if you couldn't identify the first light?
• d) What additional safety measures would you take for a night entry?

Scenario: You are preparing your navigation system before a coastal passage. Correct setup is the foundation of safe electronic navigation.

Tasks:

• 1. Measure (or research) your boat's actual draft, beam, and air draft. Enter these into your vessel profile and verify the system uses them for depth warnings and route planning.
• 2. Set up a depth alarm at your draft plus 1.0–1.5 metres safety margin. Record the value you chose and explain why.
• 3. Configure an anchor alarm for a realistic swing circle. What radius did you set and why?
• 4. Download the charts for your local sailing area for offline use. Verify they load correctly with no data connection (turn off Wi-Fi/mobile data to test).
• 5. Experiment with overlays: turn on satellite imagery and relief shading. Zoom into a harbour entrance you know and compare what the vector chart shows with the satellite image. Note any differences.

Scenario: Choose a familiar passage — from your marina to a nearby harbour or anchorage, ideally 10–30 nautical miles.

Tasks:

• 1. Create a manual route from your departure point to your destination. Place waypoints to clear hazards, mark turning points, and follow safe water. Check every leg at multiple zoom levels.
• 2. Record the total distance and estimated passage time for your manual route.
• 3. Now create an autoroute between the same two points. Compare it to your manual route: Where does it add unnecessary waypoints or detours? Does it route through areas you'd avoid? What's the distance difference?
• 4. Edit the autoroute to improve it based on your local knowledge. Delete unnecessary waypoints, add better ones, and adjust legs that don't make sense.
• 5. Zoom in to maximum scale on every leg of your final route. Note any hazards that only become visible at close zoom.

Scenario: Your route crosses a bar with 2.5 metres charted depth. Your boat draws 1.9 metres and you want 0.8 metres under-keel clearance (total of 2.7 metres needed).

Tasks:

• 1. Calculate how much tide height you need above chart datum to cross safely. (Hint: 2.7m needed minus 2.5m charted = 0.2m tide needed.)
• 2. Using the Rule of Twelfths, calculate the times when the tide reaches 0.2 metres or higher. Determine your safe crossing window.
• 3. Now check this on your electronic chart. Does your plotter or app show tidal information for this area? How does it display depth relative to tide state?
• 4. Consider: does your plotter adjust charted depths for predicted tide height, or does it show only the static chart datum depths? How would this affect your decision-making?

Scenario: You're approaching a harbour entrance. Your GPS shows you 200 metres from the entrance buoy, but you can clearly see the buoy and it looks about 400 metres away. Your depth sounder shows 8 metres, but the chart shows 15 metres at your GPS position.

Tasks:

• 1. List at least three possible causes for this discrepancy between what your GPS says and what you observe.
• 2. What would you do immediately? Would you trust the screen or your observations?
• 3. What methods would you use to verify your actual position? List at least three.
• 4. Would you continue at the same speed, slow down, or stop? Explain your reasoning.
• 5. Reflect: how would this situation be different if you had no traditional navigation skills and relied entirely on the screen?