Marine Navigation Basics – How to Navigate a Boat
Whether your watercraft of choice is a speedboat, yacht, or something in between, knowing the basics of marine navigation is absolutely essential when you’re spending time on the water. Below is Van Isle Marina staff’s quick guide to the basics of navigation. We’ve included some short definitions to go with our roundup of the traditional manual tools that truly experienced sailors swear by, as well as electronic devices with all the bells and whistles.
Marine Navigation – Learning Your Directions
Latitude & Longitude – A coordinate system that allows you to pinpoint exactly where you are on Earth, whether on land or at sea. Latitude measures north & south, while longitude measures east & west.
True North – Also known as geodetic north, this marks the position of the geographic North Pole according to the position of the Earth’s axis. Not to be confused with the magnetic North Pole, which shifts by kilometres every year due to moving sea ice, the geographic North Pole is where the lines of longitude converge. The same is true for the South Pole.
Knots – 1 knot or kn is 1.15 mph or 1.852 km/h, a measure of speed for boats and aircraft. This unit of measurement has been used since the 17th century, when the speed of ships was measured by a rudimentary device made of coiled rope with evenly spaced knots.
This rope was attached to a pie-shaped piece of wood that floated behind the ship and was let out for a certain amount of time. When the line was pulled back in, the number of knots (roughly the speed of the ship) between the wood and the ship were counted.
Nautical Mile – A nautical mile is equal to one minute of latitude and is based on the Earth’s circumference. One nautical mile equals 1.1508 statute (land measured) miles.
Marine Navigation – Tools
Magnetic Compass – Tried and true, and something that every sailor should have on hand since it doesn’t require any electricity to operate. The magnetic compass points to magnetic north and you can read your direction using the needle or the “lubber line.” There are 360 degrees, with 0 degrees to the north, 180 degrees to the south, 90 degrees to the east, and 270 degrees to the west. The direction your boat is heading in measured in degrees relative to magnetic north.
Rules – A set of parallel rulers that determine the angle (degrees) between the starting point and destination. They are attached by swivelling arms that you can “walk” across a nautical chart, while maintaining the correct angle.
Dividers – Used to measure distance on a nautical chart, dividers are used to separate two points on the chart to represent one or many nautical miles.
GPS – Global Positioning System (GPS) devices receive signals from satellites to pinpoint your position, plot your course, and determine speed. They’re increasingly popular among boaters for their simplicity, ranging from very basic to high end, complete with depth alarms and chart plotters, among other extras.
Marine Navigational Aids
Buoy – An anchored buoy serves as a marker for watercraft. Port hand buoys are green and mark the left side of a passage, or an obstruction in the water. Starboard hand buoys are red and mark the right side of a passage, or an obstruction in the water. A simple rule is to keep green buoys on the left side and red buoys on the right to keep with traffic and avoid hazards. Buoys also come in different shapes and sizes.
Cardinal Marks – There are north, south, east, and west cardinal buoys, which mark the safest direction to travel. These may have a white light on top that each follow a specific pattern, and they’re coloured for easy direction identification:
- North- Painted black on top, yellow on bottom
- South- Painted yellow on top, black on bottom
- East- Painted black on top and bottom, yellow in the middle
- West- Painted yellow on top and bottom, black in the middle
Lights – Lights used on buoys for marine navigation are all assigned specific patterns of speed and number of flashes. Cardinal buoys have white lights with a flashing speed and pattern that corresponds to the position on an analog clock. For instance, east buoys flash at a rate of 3 times every 10 seconds. Special types of buoys, like anchorage buoys and cautionary buoys have a yellow light that flashes once every 4 seconds.
Paper Charts – A paper chart is still the most reliable form of charting when on the water and is used to plot courses between point A and point B, determine depth of water, any charted obstructions, navigation aids, and information on currents and tides.
Electronic Charts – The Electronic Navigational Chart (ENC) uses computer software and databases to provide details for charting when on the water, ENC’s use a dynamic map that shows your location in real time. The most complex are Vector charts, which allow you to filter out any layers of
information you may not need at all times, such as location of buoys, direction of current or depth of water. This navigational tool can be used on a waterproof chart plotter, smartphone or tablet, and laptop.
PARTS OF A BOAT
PARTS OF A BOAT: BOATING TERMINOLOGY FOR BEGINNERS
If you’re new to the boating community, familiarizing yourself with the different parts of a boat will help you talk the talk and ensure you set sail with confidence. We have you covered with our handy beginner’s guide to the different parts of a boat. From the bow to the stern, and everything in between (the hull), know before you go!
- Anchor: a large heavy object attached to a boat that is dropped into the water and attaches itself to the seabed to keep the boat in place when desired.
- Awning: an often-retractable cover used to shield passengers from the weather.
- Ballast: a large amount of weight (often lead) added to the boat used to better stabilize it.
- Berth: the sleeping quarters of the boat.
- Bilge: the lowest section of your yacht where water is collected, near the shower sump.
- Bimini top: a canvas cover or similar used to occasionally shield passengers from the weather.
- Bow: the entire front portion of the boat.
- Bridge: the part of the boat where the controls are; the cockpit.
- Bulkhead: a supportive structure between the bulk and the deck.
- Cabin: private living quarters, usually below deck, where people sleep or otherwise spend time indoors.
- Casting platform: an open area used to cast fishing rods.
- Coaming: edging added to a cockpit to keep out water.
- Console: a smaller area above a deck or cockpit offering guests more space to gather.
- Deck: the part of the boat that is on top of the hull and an area where you can walk or work. It acts as a roof for the hull. Boats can have multiple decks (i.e. foredeck).
- Dinghy: a smaller boat on board the larger boat uses to get to land easier or as a life-saving apparatus.
- Fenders: parts made of plastic or rubber that act as a buffer between the boat and the dock or pier and other boats, protecting both from damage.
- Foredeck: the front-most deck of the boat in boats that have multiple decks.
- Flybridge: a steering station on specific models that is on top of the boat’s cabin. See the Riviera 57 Enclosed Flybridge as an example.
- Galley: the kitchen area where food is prepared.
- Gunnel/Gunwale: The edge running along the side of the boat, adding structure and strength to the vessel’s design.
- Hatch: an opening connecting the bottom of the boat with the deck. There can be many hatches on a boat. Moving down into the hatch is “going below” and moving up through the hatch is “going topside.”
- Head: the bathroom on board.
- Helm: the wheel used to steer the boat.
- Hull: the body (shell) of the boat that encompasses other parts like the deck, bottom, and sides. The hull doesn’t include the rigging or mast of a sailing yacht.
- Keel: a part of the hull, the keel is the primary middle beam running from the front (bow) to the back (stern). It is considered the foundation of a boat, ship, or yacht.
- Jump seats: Space-saving small seats you can pop in and out of place in the cabin.
- Lifeline: lines or cables that act as guard rails, preventing people or gear from falling overboard.
- Line: a synonym for rope used in the boating world.
- Mooring: a place where you can safely secure your boat, such as a marina (a dock, wharf, or pier).
- Port: as you’re facing the bow, the port side of the boat is the entire left side.
- Porthole: a window in the side of the boat, often circular.
- Propellers: the blades of a motor that spin and propel the boat.
- Rigging: the lines used to operate the sails, masts, and yards.
- Rudder: a vertical appendage attached to the hull and submerged in the water to control steering.
- Saloon: the primary dining area onboard.
- Scuppers: drains on the deck used to spray incoming water from rain and waves overboard.
- Starboard: as you’re facing the bow, the starboard side of the boat is the entire right side.
- Stern: the back of the boat.
- Superstructure: anything above the deck that is not the rigging is part of the boat’s superstructure.
- Swim deck/platform: an area for swimming, located far away from the casting platform when a boat has both.
- Tender: another name for a dinghy.
- Thruster: located on the sides of ships and some yachts, thrusters are used to move the bow or stern sideways in either direction through the water without changing the vessel’s orientation.
- Topside: the part of the hull that is not touching the water.
- Underside: the part of the hull that is touching the water.
This is an advanced online course on marine navigation, providing you with the “conditio sine qua non” ofoffshore sailing.
Nowadays most sailors tend to rely on modern equipment like differential GPS or Radar to navigate them through hazardous waters. Not only is such reliance unwanted and possibly dangerous, also the act of navigating by yourself is actually a lot of fun.
What is navigation?
“Navigare necesse est, vivere non est necesse” is latin for: to sail is vital, to live is not. This phrase tells us that both sailing and the “conditio” of positioning are highly intertwined. Indeed, the art of navigation enables you to set a course and sail to your destination by using only nautical charts, a compass and your common sense. The aim of this course is to teach you how to navigate safely while using the minimum of resources: methods that have been in use since the Middle Ages, and are still applied by the professionals .
This course gives you the insight and feel of a seasoned navigator.
Skip over navigation The earth can be regarded as a spherical object, and since we're dealing with a 3-dimensional shape we need coordinates of a different form than the usual x- and y-axes.
Skip over navigation The nautical chart is a 2-dimensional representation of a 3-dimensional world. And although this results in various distortions, as long as two requirements are met we can use this image for navigational purposes. The angles between three objects in the chart should be the same as the angles between the real objects which they represent.
Skip over navigation In China compasses have been in use since the Han dynasty (2nd century BCE to 2nd century CE) when they were referred to as "south-pointers". However at first these magnets were only used for geomancy much like in the art of Feng Shui.Eventually, during the Sung dynasty (1000 CE) many trading ships were then able to sail as far as Saudi Arabia using compasses for marine navigation.
Skip over navigation The modern chart shows us positions of many recognizable aids to navigation like churches and lighthouses, which facilitate the approach to a coastal area. This concept originated from a chart by Waghenaer and proved a milestone in the development of European cartography.
Skip over navigation The Doubled angle on the bow fix resembles a running fix though only one navigation aid is used. α = 30° , β = 60°δ = 120° , γ = 30°Isosceles d1 = d2 In the example on the right the initial angle (30°) on the bow is doubled (60°) yielding an isosceles triangle .
Skip over navigation Definition:tide - from the sailor's perspective - is the vertical rise and fall of the sea level surface caused primarily by the change in gravitational attraction of the moon, and to a lesser extent the sun.
Skip over navigation The depths and heights in the chart need a plane of reference: the chart datum (CD). Depths are usually described with respect to low water reference planes (yielding lower charted depths, which are safer), and heights are shown with respect to high water reference planes (again, yielding lower vertical clearances on the chart, which are safer).
Skip over navigation Currents reflect the horizontal movement of water whereas tides reflect vertical movements. These currents influence the ship's position and are therefore important to understand. The horizontal movement is primarily caused by the gravitational pull of celestial bodies.
Skip over navigation Aids to navigation are special structures like lighthouses, lightships, beacons, buoys, etc that are used to enhance safety by providing more opportunities to obtain LOPs.These lights and marks are prescribed across the world by the International Association of Lighthouse Authorities (IALA).
Skip over navigation Masthead light A white light placed over the fore and aft centreline of the vessel showing an unbroken light over an arc of the horizon of 225° and so fixed as to show the light from right ahead to 22.5° abaft the beam on either side of the vessel.