Learn to sail aboard Fika
Take the helm of a model of Fika with her sails up. Steer, trim the sheets, and work through a few short lessons on how a sailboat uses the wind. Drag the view to look around her.
Sailing simulator
This simulator needs a browser with 3D graphics (WebGL) turned on.
No-go zone Lesson goal Sail works Best trim
Anchoring: how much rode?
Scope is how much rode you let out compared with the height from your bow roller to the bottom. Enough scope lets the pull reach the anchor flat along the seabed, which is what keeps it dug in. Too little, and the rode tugs the anchor upward and can pull it out. Play with the depth, the rode, and the wind below.
- Scope
- --
- Pull at the anchor
- --
- Chain lying on the bottom
- --
- Swing circle (radius)
- --
Rules of thumb. With all chain, about 5:1 scope in settled weather, 7:1 or more when it blows. With mostly rope, 7:1 to start. Always add the tide that's still to come and the height of your bow roller, not just the depth on the sounder.
Why chain helps. Its weight hangs in a curve, the catenary, so the pull reaches the anchor flat and the curve soaks up the boat's surging. In a hard blow the chain straightens out, which is why storm scope is longer. Watch the curve flatten as you raise the wind.
Mind your swing. More rode means a bigger circle when the wind shifts. In a crowded anchorage, everyone's circles have to fit.
Assumes a bow roller about 6 ft above the water and 1/2 in G4 chain at about 2.5 lb/ft. The pull from the wind is a rough estimate for a boat of Fika's size in steady wind, before gusts and surging, so treat the numbers as a guide, not a substitute for judgment.
The night sky, and finding your way by it
The sky as it looks from our last shared stop. Slide through the night, tap a star to see how high it is and which way to look, and see how navigators used these same stars to find their position at sea.
North is at the top and east on the left, as if you're lying on your back looking up. The edge of the circle is the horizon.
Polaris tells you your latitude
Polaris, the North Star, sits almost exactly above the North Pole, so its height above the horizon is very nearly your latitude.
The noon sight
At local noon the sun is at its highest. Measure that angle with a sextant, and with the sun's declination from the almanac you have your latitude. The time noon happens gives your longitude: the sun moves 15° of longitude an hour, so every 4 minutes it's late is 1° farther west.
Star sights at twilight
At dawn and dusk there's a short window when both the brightest stars and a sharp horizon are visible. A navigator measures the height of three or more stars, each one giving a line of position, and where the lines cross is the ship. Turn on Navigational stars to see the 57 stars in the Nautical Almanac.
Fika carries GPS, with backups. Celestial navigation is the one that needs no batteries.
A simplified model tuned to feel like a heavy 48 foot ketch, not a precise simulation of Fika's performance.