NAVIGATION TRAINING Section 3 Charts The Canadian Coast Guard Auxiliary Pacific Region has made a substantial contribution to boating safety in Canada through their successful adaptation of the United States Coast Guard Auxiliary’s Coastie program to the Canadian environment, in the form of the Bobbie the Safety Boat program.

Table of Contents • Section 1 Types of Navigation • Section 2 Terrestial Coordinates • Section 3 Charts • Section 4 Compass • Section 5 Nautical Publications • Section 6 Navigational Aids • Section 7 Buoyage • Section 8 Position Lines and Fixes • Section 9 Tides • Section 10 Currents • Section 11 Weather

Charts Chart Projections -Desirable qualities of a chart projection: 1. Maintain true shape of physical features. 2. Maintain correct proportions of features relative to one another. 3. True scale, permitting accurate measurement of distance. 4. Rhumb lines plot as straight lines. They are lines on the earth’s surface that cross all meridians at the same angle

Charts Mercator Projection All coastal charts of Vancouver Island, northern coasts of BC, Georgia Strait and ports are Mercator Charts.

Charts Mercator Projection ADVANTAGES •Position, distance, and direction can be accurately measured •True shape of features is maintained over small areas

Charts Chart Scale •The relationship between two measurements. Expressed as a ratio. •The scale to which a chart is drawn appears directly under its title.

Charts Chart Scale • Large scale chart covers a small area and are used for piloting and inshore navigation. Small scale charts are less detailed than large scale charts and cover a large area.

Charts Chart Production •The Canadian Hydrographic Service is responsible for all Canadian Charts and Publications. •See www.charts.gc.ca

Charts Types of Charts •Coastal charts: Large Scale Charts –1:50,000 - 1:150,000 For approaching bays and harbours, and used for coastal navigation showing outlying reefs and shoals.

Charts Plotting a Position 1. Determine the parallels on the chart that bracket the latitude. 2. Place the pivot point of the compass on the closest line.

Charts Plotting a Position 3. Spread the compass until the lead rests on the given latitude. 4. Move to the approximate longitude and swing an arc.

Charts Plotting a Position 5. The same process is repeated using the longitude scale and the given longitude. 6. The desired position is the intersection of these two arcs.

Charts Plotting a Position 7. If plotted correctly, the intersection should occur at the crest of both arcs.

ALWAYS use the latitude scale to determine distances Charts Measuring Distance •The latitude scale can be used to measure distances, since one degree of latitude equals 60 nautical miles, everywhere on the earth. ALWAYS use the latitude scale to determine distances on a chart.

Charts Measuring Direction • All rhumb lines on a Mercator projection represent true directions. • Measurement of direction on a Mercator chart is accomplished by using a parallel ruler to transfer the direction of a rhumb line to a nearby compass rose.

Charts Measuring Direction 045˚ True 060˚ Magnetic

Charts Correction of Charts • The Canadian Hydrographer issues weekly Notices to Mariners, which include corrections to be made to Canadian charts. • When charts are bought, they are generally corrected up to date. • Once in use Notices to Mariners should be checked and corrections to charts made as necessary.

Charts Correction of Charts • When a correction has been made, a note of the year and Notice to Mariner number should be made in the bottom left hand corner of the chart, having checked that the previous correction has been made. 2008 - 41- 74 - 86 - 127