Except aboard very small vessels, venturing beyond waters that are recognizable or narrow means you need a chart. To learn about charts, purchase one you want to navigate or download a free copy in our charts section. The chart seller can let you know which one you need. Don't Ask For A Map - From conference a map showing coastlines in addition to other information of use is called a chart. It is similar to calling the bow the end of the boat. Scale - When you are buying a detailed chart of waters, you have an option between a chart that covers a smaller area with great details or a chart that covers a bigger area in less detail.
The scale of a port map, for example, may be 1: 20, 000, meaning 1 on the chart represents 20, 000 of the planet's surface, or about 0.27 nautical miles. Which makes one mile on the water a bit less than 4 on the chart. Harbor charts would be very detailed. Crafts are purchased folded like a road map for usage on boats. The scale of small craft charts is frequently 1: 40, 000, therefore a nautical mile is about 1.8 on this scale chart. So the bigger the number after the colon, the bigger the area the chart shows the scale designation on charts is a fraction, but the smaller the scale.
So called coast charts, for instance, usually use a 1: 80, 000 scale. Which makes a nautical mile less than an inch, and lets a single chart cover a 30 miles to 40 mile area, but with less details than a large scale chart. General graphs with scales as small as 1: 1, 200, 000 cover huge areas 600 miles or more, but with little detail. Such small scale charts are helpful mainly for route planning. Depths - charts published on the water regions of the chart indicate your depth of your water at that spot.
Nevertheless, a 2 on the chart could mean two feet , two fathoms, or two meters. This is obviously shown on the face of the graph in big print SOUNDINGS IN FATHOMS AND FEET, for instance. A fathom, by the way, is six feet, so on a chart with surveys in fathoms, a number like 03 means zero fathoms and 3 feet. The water in this spot is 3 feet deep at MLLW. A sounding of 55 will be 35 feet.
Nevertheless, when the tide table reveals a negative low tide entry, actual depth would be less than the chart indicates. When the depth of your water is an issue, you'll have to be familiar with the height of the tide. Contour Lines - Additionally to numerical depths, graphs show depth contour lines.
The scale of a port map, for example, may be 1: 20, 000, meaning 1 on the chart represents 20, 000 of the planet's surface, or about 0.27 nautical miles. Which makes one mile on the water a bit less than 4 on the chart. Harbor charts would be very detailed. Crafts are purchased folded like a road map for usage on boats. The scale of small craft charts is frequently 1: 40, 000, therefore a nautical mile is about 1.8 on this scale chart. So the bigger the number after the colon, the bigger the area the chart shows the scale designation on charts is a fraction, but the smaller the scale.
So called coast charts, for instance, usually use a 1: 80, 000 scale. Which makes a nautical mile less than an inch, and lets a single chart cover a 30 miles to 40 mile area, but with less details than a large scale chart. General graphs with scales as small as 1: 1, 200, 000 cover huge areas 600 miles or more, but with little detail. Such small scale charts are helpful mainly for route planning. Depths - charts published on the water regions of the chart indicate your depth of your water at that spot.
Nevertheless, a 2 on the chart could mean two feet , two fathoms, or two meters. This is obviously shown on the face of the graph in big print SOUNDINGS IN FATHOMS AND FEET, for instance. A fathom, by the way, is six feet, so on a chart with surveys in fathoms, a number like 03 means zero fathoms and 3 feet. The water in this spot is 3 feet deep at MLLW. A sounding of 55 will be 35 feet.
Nevertheless, when the tide table reveals a negative low tide entry, actual depth would be less than the chart indicates. When the depth of your water is an issue, you'll have to be familiar with the height of the tide. Contour Lines - Additionally to numerical depths, graphs show depth contour lines.
