Downwind Sailing

Downwind sailing – sailing in a reaching/running wind with the wind from astern – is often the fastest but also the most demanding phase of a regatta leg. On the leeward leg, it is decided whether you can extend a lead from a good windward mark rounding or make up a deficit. Those who master VMG (Velocity Made Good), sail selection, and boat weight gain boat lengths without risky maneuvers. Those who simply "sail straight to the target" lose to competitors who actively use course angles, pressure zones, and waves.

This guide summarizes the technical fundamentals, trim variants, and typical regatta situations – from single-handed dinghies to crews with spinnakers on keelboats. You can find the basic terminology for reaching/running wind under Close-hauled and Reaching/Running Wind; for VMG calculation under Courses and VMG.

What Downwind Sailing Means in Regatta Racing

In regatta sailing, downwind refers to any leg on which the target (or the next mark) lies to leeward – typically the second half of a windward-leeward course. The True Wind Angle (TWA) is usually between 120° and 180°. Depending on the boat class, you sail with mainsail only, with spinnaker, gennaker, or in wing-on-wing (mainsail and headsail on opposite sides).

Downwind is not synonymous with "wind directly from behind." The most effective VMG is almost always on reaching courses to the left and right of the direct course to the target – comparable to tacking upwind, but in reaching/running wind. Helmsman and onboard strategist choose the angle that delivers the highest speed toward the target mark.

Downwind vs. Upwind – Key Differences

Optimizing VMG and Course Angles

Velocity Made Good is the benchmark for every course decision downwind. A boat sailing 8 knots but deviating only 120° from the target can have a higher VMG than one doing 9 knots on a direct course. Helmsman and tactician continuously compare:

1. Boat speed (BS) – What does the current course deliver?
2. True Wind Angle – Where is the optimum for this wind strength?
3. Target direction – Which angle maximizes the component toward the mark?

In under 8 knots, most classes sail deeper (larger TWA, closer to the direct course) because speed is lacking and every degree of VMG counts. In more wind and with planing mode dinghies, a higher course (smaller TWA) pays off to use speed and surf effects.

Sailing by the Lee and Wind Shadow

Sailing by the lee means: the boat sails with the wind slightly from the opposite quarter than the mainsail – an unstable but sometimes VMG-strong course. Advantage: you can "blank" competitors (give them your wind shadow). Disadvantage: the boat tends to broach (uncontrolled windward turn). Only experienced crews use this technique deliberately and briefly.

Sail Selection and Trim Downwind

The right sail area decides speed and control. On keelboats, spinnaker sets are standard crew work – procedure and roles under Spinnaker Set and Drop. For broader winds and heavier boats, the Gennaker and Code Zero comes into play.

Wing-on-Wing

In wing-on-wing, the headsail is on the windward side and the mainsail on the leeward side. Typical for courses near 180° TWA. Important:

• Pole (spinnaker pole on the headsail) set correctly and height trimmed
• Backwind strategy – headsail may backwind slightly, mainsail twisted
• Crew weight to windward for stability in gusts

Spinnaker Trim in Four Steps

1. Lower the pole – spinnaker luff tight, not too far forward
2. Sheet trim – pull the clew until the first fold appears on the luff, then ease 2–3 cm
3. Guy/foreguy – stabilize course, avoid overtrim
4. Twist – in gusts open the spinnaker (ease sheet), in lulls trim in again

Details on mainsail and headsail trim without spinnaker can be found under Mainsail and Headsail Trim.

Using Surfing and Waves

Planing boats (470, 49er, many dinghies) gain massively downwind through surfing. Catching a wave means: raise the course slightly, shift boat weight aft, maintain sail pressure – then ride the wave and rebuild VMG.

Practical Rules for Surf Sailing

• Read waves – recognize largest set waves early, don't chase every wave
• Crew communication – "Wave left", "Surf now" – clear calls
• Don't over-sail – too much pressure leads to broach instead of speed gain
• Gybe timing – plan gybes in flatter seas or between wave troughs

Maneuvers and Crew Work on the Leeward Leg

Downwind is dominated by gybing and spinnaker handling. A clean gybe saves seconds and avoids damage – technique and variants under Roll Tack and Roll Gybe as well as the overview Tacking and Gybing.

Typical sequence before a leeward gate:

1. Prepare spinnaker trim for approach
2. Coordinate gate decision (left/right) with tactician
3. If necessary, pre-gybe or gybe-set depending on gate and fleet position
4. Spinnaker drop or peel following mark rounding

At gate roundings in reaching/running wind, overlap and room are critical – see Leeward Gates and Overlap.

Common Mistakes and How to Avoid Them

The following mistakes regularly cost places on the leeward leg:

• Sailing too deep – high boat speed, but poor VMG toward target
• Spinnaker overtrimmed – boat becomes unstable, luff constantly collapses
• No gybe planning – spontaneous gybes under pressure end in chaos
• Ignoring dirty air – "suffocating" behind larger boats or in the fleet
• Weight distributed incorrectly – leeward capsize in gusts instead of windward stabilization

Checklist: Downwind Before and During the Leg

Preparation at the Windward Mark

• Check wind strength and gusts for sail selection
• Discuss gate plan and first gybe option
• Spinnaker/gennaker ready, lines untangled
• Instruments: TWA, BS and VMG in view

During the Leg

• Question VMG course every 30–60 seconds
• Actively use pressure zones and fleet position
• Continuously trim spinnaker luff and sheet
• Confirm gybe ho and crew position before each gybe
• Plan approach to gate/mark with speed, not just course

Downwind Training

• Record VMG polars with GPS
• Wing-on-wing exercises
• Spinnaker set from various courses
• Controlled gybe in increasing wind strength
• Deliberately approach surf waves
• Film gate rounding with coach boat
• Dirty air exercises with training partner
• Leeward drop under time pressure

Related Topics

• Close-hauled and Reaching/Running Wind
• Courses and VMG
• Spinnaker Set and Drop
• Tacking and Gybing
• Leeward Gates and Overlap