⛵ Sail Trainer points of sail, tacking & jibing
Drag the boat to steer  ·  drag the water to move the wind  ·  or use ← → keys
Steer with the ◀ ▶ buttons or ← → keys. The boat sails itself forward.
Drag the boat to turn it  ·  wind always comes from the top here

The Sailor's Field Guide

Every term used in this app, plus the one big idea that ties it together.

The big idea: how do I get from A to B?

A sailboat cannot sail straight into the wind. There is a wedge of roughly 90° pointing at the wind — the no-go zone — where the sails just flap and the boat stops.

If B is upwind: aim as close to the wind as you can (close-hauled, ~45° off the wind), sail a while, then tack — swing the bow through the wind onto the other side — and sail close-hauled again. Repeat. The result is a zig-zag staircase called beating to windward. You sail further than the straight-line distance, but it's the only way up.

If B is downwind: you have it easy — you can point much more directly. Sail on a broad reach and jibe (swing the stern through the wind) when you want to switch sides. Sailing dead-downwind works but is slow and risks the boom slamming across by accident.

If B is across the wind: easiest of all — a reach. Point the boat at it and go. No tack, no jibe needed.

Watch out — "tack" means two different things.
1. Your tack = which side the wind hits. Wind over the right (starboard) side → you're on starboard tack. Wind over the left → port tack.
2. To tack = the maneuver of turning the bow through the wind, which swaps you from one tack to the other.
Same word, related ideas. When someone says "tack the boat" they mean the maneuver.

See it — the boat & its lines

Anatomy of a sloop

A "line" is sailor-speak for a rope — almost nothing on a boat is called a rope. The two lines you adjust constantly are the sheets: they control how far in or out each sail is. The halyard hoists a sail up. The grey wires are stays — fixed rigging that holds the mast up; you never touch those while sailing.
WATERLINE Masthead Mast Mainsail Boom Jib Forestay Backstay Halyard Mainsheet Jib sheet Tiller Rudder Keel Hull Bow ▸ ◂ Stern
Sheets & halyard — lines you handle Stays — fixed rigging Spars — mast & boom

↺ Tacking

Used to change course while sailing upwind. The bow swings up through the eye of the wind. The boat slows for a moment and the sails cross over gently. Keep your speed up so you don't stall in irons.
NO-GO ZONE WIND bow swings INTO the wind

↻ Jibing

Used to change course while sailing downwind. The stern swings through the wind. The boom slams across hard and fast — sheet it in first, then ease out, so it doesn't crash over.
WIND bow swings AWAY from the wind
This is a simplified practice simulator. Real sailing adds apparent wind, tides & current, waves, heel, right-of-way rules and other boats. Use this to build intuition — then take a proper on-the-water course.