| Abeam | At approximately right angles to the fore and aft line of a boat. |
| Apparent wind | The wind affecting the sails of a boat in motion, combination of the true wind and the boat speed generated wind. |
| Backwind | Turbulent airflow in the wake of the sail(s) |
| Bear away | Change direction away from the wind |
| Beat | The upwind leg, towards the wind mark. Sailing close-hauled |
| Broach | The boat heels over heavily, to the point the rudder looses grip (stalls) and the boat turns up against the wind. see also the Wikipedia definition |
| Draft | The depth of the sail. Measuring the concavity of the sail in a horizontal cross section. We also often look the where the maximum draft appears in % from the leading edge. |
| Gust | A sudden increase in wind speed (pressure) – a wind gust. |
| Header | A wind shift toward the leeward side of the boat, opposite to a lift. Also known as “getting knocked”. Helmsman needs to bear away to keep the same wind angle. |
| Leech | The aft edge of the sail. Can be either closed with the top batten hooked to windward, or open with the top batten aimed to leeward. |
| Lift | A wind shift toward the windward side of the boat, opposite to a header. |
| Luff | 1. Turning the boat to windward so that the leading edge of the sail starts to break, i.e. fall in.2. The fore edge of a mainsail, headsail or spinnaker. |
| Lull | Opposite of a gust. A temporary reduction in wind strength/pressure. |
| Oscillating shift | Wind shift where the wind direction keeps changing back and forth with a certain frequency. Normally a few minutes in between these shifts but can vary. |
| Persistent shift | Wind shift which isn’t changing back to the original wind direction. Often happens when the sea breeze kicks in. |
| Reach | Sailing in a direction which is in between a beat and a run. Sails not sheeted close hauled. A “tight reach” or “open reach” is a way of further clarifying the angle of the reach. |
| Starboard end | The starboard end of the starting line (normally near the committee boat). Also referred to as the windward end or weather end. Opposite side of the port end. |
| Point | Steer at the highest possible angle towards the wind, still keeping good boat speed. |
| Strategy | Longer term planning. Could relate to a race, or a whole season, race series or campaign including e.g. sails to purchase, what to focus practice sessions on, which end of the course seems to be the favored side in terms of wind and current etc etc. This is a very wide concept. |
| Tack | 1. A maneuver by which a sailing boat turns its bow through the wind, verb: Tacking
2. The lower corner of a sails leading edge |
| Tactics | Short term decisions regarding how to maneuver the boat in order to optimize it’s position in relation to other boats. A good knowledge of the racing sailing rules is a must to exercise good tactics. |
| Trim | The command “trim!” or “trim me” means pull in the sheet, where as “ease” is the opposite. “Perfect trim” means keeping the sheets perfectly sheeted for the current conditions. |
| True wind | The wind strength and direction affecting a static object, i.e. if the boat isn’t moving then this is the wind it would experience. |
| Twist | The amount the sail(s) open up at the upper half. A twisted sail will have the top batten aimed to leeward. In a heavier breeze it’s often efficient to have some twist in the sails to reduce the power, and also in very light breeze or when you try to accelerate the boat some twist is needed. |
| Upwind | (Sailing) to windward. |
| VMG | Velocity Made Good. The speed to windward (when going upwind) or to leeward (when going downwind on a reach). By optimizing the vmg you know that you’re heading towards the next mark in the fastest way you can – although it doesn’t take into account e.g. wind shifts. |
| Wind shift | Change of direction of the true wind. Can be persistent or oscillating. |
