Basic Coastal Navigation

The Four Phases of Voyage Planning

The navigator bears primary responsibility for the safe passage of the vessel. Every voyage follows a four-phase planning cycle:

The Vessel Log

A properly maintained log is both a legal requirement and a critical navigation tool. Record these at regular intervals:

• Position — Latitude and longitude (from GPS or fix)
• Course & Speed — Heading steered and speed over ground
• Weather — Wind direction/speed, visibility, barometric pressure
• Sea State — Wave height and direction
• Fuel & Water — Remaining levels
• Incidents — Any notable events, equipment issues, or sail changes

Nautical Charts

Nautical charts are the navigator's primary tool. Understanding chart scale is fundamental:

• Large scale — Covers a small area with great detail (e.g., 1:10,000 for harbours)
• Small scale — Covers a large area with less detail (e.g., 1:500,000 for ocean passages)

Charts use a grid of latitude (horizontal lines, measured N/S from the equator) and longitude (vertical lines, measured E/W from the Prime Meridian). Modern Canadian charts use the WGS84 datum, which ensures GPS positions align accurately with chart positions.

Depths (soundings) are shown in metres and are reduced to chart datum (lowest normal tide). Drying heights — areas that uncover at low water — are shown underlined. Depth contour lines connect points of equal depth, helping you visualize the seabed.

Chart 1: Symbols & Abbreviations

Chart 1 is the essential reference book that explains every symbol and abbreviation used on Canadian nautical charts. It is organized by category:

• Topography — Coastline features, landmarks, buildings
• Hydrography — Depths, bottom types, currents, tides
• Aids to Navigation — Buoys, beacons, lights, fog signals
• Dangers — Rocks, wrecks, obstructions, restricted areas

Every navigator should have a copy of Chart 1 readily accessible when working with charts.

Essential Publications

Canadian navigators rely on several key government publications:

Notices to Mariners & NAVWARNs

Notices to Mariners are published weekly and contain corrections to charts and publications — new hazards, changed buoys, updated depths. Always apply the latest notices before using a chart.

NAVWARNs (Navigational Warnings) are urgent safety broadcasts transmitted by radio. They alert mariners to immediate hazards such as unlit buoys, new obstructions, or military exercises. Monitor VHF and Navtex for these broadcasts.

Essential Navigation Instruments

Every coastal navigator must be proficient with these tools. Modern electronics supplement but never replace traditional instruments.

Chart Datum & Factors Affecting Depth

The depth shown on a chart (sounding) is measured from chart datum — the lowest level the tide is predicted to reach under normal conditions (Lowest Normal Tide in Canada). Actual depth at any time = charted depth + height of tide above datum.

Factors affecting actual water depth beyond tides:

• Atmospheric pressure — High pressure pushes water down; low pressure allows it to rise
• Wind — Sustained onshore winds can raise water levels significantly
• River flow — Spring runoff increases water levels in estuaries
• Storm surge — Combined effect of low pressure and wind during storms

Using Tide Tables

Canadian Tide & Current Tables (published annually by CHS) provide predicted times and heights of high and low water for reference ports, plus corrections for secondary ports.

Steps to find tide height at a secondary port:

1. Find the reference port predictions for your date
2. Look up the secondary port corrections (time difference & height ratio)
3. Apply corrections to get local predictions
4. Use the Rule of Twelfths for heights between high and low water

The Rule of Twelfths

The tide rises and falls in a predictable pattern over approximately 6 hours between high and low water. The Rule of Twelfths divides this into six one-hour intervals:

The pattern is 1-2-3-3-2-1. The middle two hours see the most change (3/12 each = half the total range), while the first and last hours see the least.

Three Types of North

Understanding the relationship between three "norths" is fundamental to coastal navigation:

The Conversion Formula

To convert between True, Magnetic, and Compass courses, remember: TVMDC

Example: True course 045°, Variation 15°W, Deviation 3°E
Magnetic = 045° + 15° (West, so add) = 060°M
Compass = 060° − 3° (East, so subtract) = 057°C

Dead Reckoning (DR)

Dead reckoning is estimating your current position by advancing a known position using your course steered and distance traveled. A DR position is plotted as a small circle on the chart with the time noted.

DR does not account for the effects of current, wind (leeway), or steering error — it is your best estimate based solely on course and speed.

Position Fixes

A fix is an accurate position determined by observation. Methods include:

• Cross Bearings — Take bearings to two or more charted objects. Where the bearing lines cross on the chart is your fix. Three bearings create a "cocked hat" — you are somewhere inside it.
• Bearing and Distance — One bearing to a charted object plus a radar distance or visual range gives a fix.
• Bearing and Depth Contour — A single bearing combined with a depth reading that matches a specific contour line.
• GPS Position — The most common modern fix, but always cross-check with visual observations when possible.

A fix is plotted as a small triangle with the time noted.

Danger Bearings

A danger bearing is a bearing line drawn on the chart that defines the boundary of safe water. If your bearing to a charted object crosses the danger bearing, you are too close to a hazard.

Danger bearings are drawn with a hatched line on the hazard side — stay on the clear side.

ETA Calculations

The fundamental navigation formula:

Example: Distance 24 NM, Speed 6 knots → Time = 24 ÷ 6 = 4 hours. Depart 0800 → ETA 1200.

Canadian Aids to Navigation (IALA Region B)

Canada uses the IALA Maritime Buoyage System Region B. The fundamental rule for lateral marks is “Red Right Returning” — keep red buoys to your starboard (right) side when returning from sea (heading toward the harbour).

Lateral Marks

Cardinal Marks

Cardinal marks indicate where the safe water lies relative to the mark. Named for the compass direction of the safe water. They use black and yellow colour bands with distinctive topmarks:

Special Marks

Preparing a Pilotage Plan

A pilotage plan is your detailed guide for navigating from departure to arrival. It transforms the four phases of voyage planning into a practical, step-by-step document.

Weather Considerations

• Environment Canada Marine Forecast — Check before every departure
• VHF Weather Channels — Continuous Marine Broadcast on WX channels
• Barometer Trends — Rapidly falling pressure warns of approaching storm
• Wind vs. Current — Wind opposing current creates steep, dangerous seas
• Fog — Common on the Great Lakes and Atlantic coast; plan for reduced visibility

Pilotage Plan Checklist

GNSS / GPS

The Global Navigation Satellite System (GNSS) — primarily GPS — has revolutionized marine navigation. A GPS receiver calculates position by measuring the time signals take to arrive from multiple satellites.

Critical principle: GPS should supplement, not replace, traditional navigation skills. Always maintain a plot on a paper chart as backup.

Electronic Charts

Two main types of electronic charts:

• Raster Charts (RNC) — Digital scans of paper charts. Familiar appearance, but limited zoom flexibility. What you see is exactly a paper chart on screen.
• Vector Charts (ENC) — Database-driven charts where each feature is a data object. Can be queried, customized, and seamlessly zoom between scales. Used in ECDIS systems.

Electronic charts on a tablet or chartplotter are convenient but are NOT a substitute for carrying corrected paper charts on recreational vessels.

AIS — Automatic Identification System

AIS automatically broadcasts and receives vessel information via VHF radio. It helps you see and be seen by other vessels equipped with AIS.

AIS broadcasts:

• MMSI (Maritime Mobile Service Identity) — unique vessel ID
• Position (latitude/longitude from GPS)
• Course Over Ground (COG) and Speed Over Ground (SOG)
• Vessel name, type, and dimensions
• Destination and ETA (if entered by crew)

Sail Canada Uniform Navigation Symbols

When plotting on a chart, use these standardized symbols so any navigator can read your work:

Exam Information

The 17 Learning Objectives — Summary

1. Navigator’s role and responsibilities
2. Chart symbols and conventions (Chart 1)
3. Canadian government navigation publications
4. Required publications for coastal passages
5. Notices to Mariners and NAVWARNs
6. Navigation instruments and tools
7. Factors affecting depth and chart datum
8. Tide and Current Tables
9. True, magnetic, and compass course conversions
10. Chart plotting: DR, fixes, danger bearings
11. ETA calculations
12. Canadian Aids to Navigation System
13. Pilotage plan preparation
14. GNSS/GPS systems
15. AIS system
16. Vessel log information
17. Sail Canada Uniform Navigation Symbols