Foiling Tacks and Gybes

Foiling tacks and foiling gybes are the most demanding course changes in modern regatta sailing. Unlike classic displacement boats, it is not just about turning quickly through or across the wind – the key is to interrupt the flight phase as briefly as possible and get back on the hydrofoil immediately after the manoeuvre. Those who master this gain several boat lengths per lap on windward-leeward courses.

This guide explains the physics, technique, and crew coordination for foiling classes such as Nacra 17, IQFoil, Moth, and America's Cup boats. It supplements the overview under Tacking and Gybing and builds on the fundamentals from What is Foiling.

Why foiling manoeuvres are different

In classic sailing, the boat loses speed during the in-irons phase and must rebuild it after the course change. In foiling: every second with the hull in the water costs massive VMG. The hydrofoil needs speed and the correct angle of attack to generate lift again. A foiling tack is therefore a controlled transition from flight to a brief displacement phase and back into flight – not a slow drift through the wind.

The key differences from displacement sailing:

• Flight height instead of waterline – control is via rudder, centre of gravity, and trim, not keel pressure
• Speed before the manoeuvre – initiated too slowly: immediate drop-off and a long displacement section
• Crew as flight controller – weight transfer directly controls foil pitch and roll
• Keep sail pressure brief – overpower during the turn pushes the bow or stern under water

Displacement vs. foiling manoeuvres

Foiling tack – technique and sequence

The foiling tack (turn through the wind) is the most critical manoeuvre at the windward mark and on the layline. In classes such as the Nacra 17, helmsman and crew work in sync to guide the catamaran through the turn without pushing both hulls into the water at the same time.

Physics of the foiling tack

1. Lift needs speed – Below take-off speed the boat drops off; every unnecessary braking extends the displacement phase.
2. Pitch control decides – Too much weight forward: bow foil loses lift. Too much aft: stern tips, hull touches water.
3. Roll stabilises the transition – Controlled roll to windward makes jib handling easier and keeps one foil airborne longer.
4. Keep rudder angle minimal – Aggressive steering creates braking pressure and destabilises flight.

Foiling tack in seven phases

1. Speed check – Boat stable in flight, VMG course maintained, no excessive heel
2. Call and initiation – "Tacking!" – begin flat windward turn, crew prepares to move to windward
3. Reduce flight height – Centre of gravity slightly forward, depower sails, descend in a controlled manner
4. Turn through the wind – Furl or transfer jib, keep mainsail set, minimal rudder
5. Brief water contact – One foil or hull touches, initiate acceleration immediately
6. Set jib – At the roll moment on the new side, trim mainsheet, crew to new lee
7. Re-flight – Weight aft, build power, trim VMG course

Crew roles in the foiling tack

In two-handed foiling catamarans, the work is clearly divided: the helmsman leads course and timing, the crew handles jib, sheet, and weight transfer. In single-handed classes such as IQFoil, a fluid body roll is more decisive than on crew boats.

Foiling gybe – technique and sequence

The foiling gybe (jibe across the wind) is considered the riskier manoeuvre. At high downwind speed, capsize, crash landing, and foil damage are a threat. Pros in SailGP and the America's Cup train gybes for days, because a single mistake can cost an entire lap.

Difference from the classic gybe

In a displacement gybe, the boat sits stably in the water; the boom is carried across the centre. In a foiling gybe:

• The boat flies at high speed – steering errors amplify immediately
• The boom must be transferred in a controlled manner without destabilising flight
• Depower before the gybe is mandatory – full sail area at 20+ knots almost always leads to a crash
• After the gybe, acceleration must begin in flight, not only after settling down

Foiling gybe in six phases

1. Depower and setup – Ease mainsail, course slightly to windward, maintain stable speed
2. Initiation – "Gybe ho!" – helmsman begins flat turn, crew in duck position
3. Mid-gybe – Boom controlled across boat centre, jib stable, weight centred
4. New tack – Mainsail on new side, crew to new lee, control foil pitch
5. Acceleration in flight – Build power gradually, not abruptly
6. Trim VMG – Find optimal downwind angle according to Courses and VMG

Boom handling and duck gybe

In fast foiling boats, the duck gybe is standard: the crew ducks under the boom while the helmsman leads the turn. Alternatively, the bear-away gybe at very high speed – here the boat is driven further bear-away before the turn begins.

More on roll techniques in the displacement context can be found under Roll Tack and Roll Gybe – many principles transfer to foiling.

Regatta tactics: when to tack, when to gybe?

On windward-leeward courses, every manoeuvre counts: at the windward mark, a clean foiling tack wins the inside position; at the leeward gate, gybe or bear-away decides depending on gate choice. In strong wind, often multiple tacks instead of risky gybes.

Common mistakes and how to avoid them

Mistakes in the foiling tack

• Turn too steep – Boat loses speed, long displacement phase
• Jib too late – In irons without drive, no take-off possible
• Weight distributed incorrectly – Bow touches first, stern lifts uncontrollably
• Overpower during the turn – Hull is pushed under water

Mistakes in the foiling gybe

• Gybe at full power – Crash landing or capsize
• Boom uncontrolled – Crew hit, flight destabilised
• Turn too slow – Boat drops off, VMG loss
• No depower beforehand – Sail pressure overwhelms foil stability

Frequently asked questions (FAQ)

Must the boat touch the water during a tack?

In most classes yes, briefly; the goal is minimal contact time.

What is harder – foiling tack or gybe?

Usually the gybe, especially at high speed and in gusts.

When to pinch instead of gybe?

From approx. 22–25 knots, depending on crew experience.

Training and checklists

Training progression

1. Control flight height – Develop pitch feel without course changes
2. Slow tacks – Practise sail handling with deliberately longer water phase
3. Speed tacks – Shorten water time, prioritise re-flight
4. Gybes in moderate wind – Duck gybe first, then bear-away as wind increases
5. Regatta simulation – Manoeuvres at windward mark and leeward gate under time pressure

Checklist: foiling tack before training

• Take-off speed and flight height known
• Jib and mainsheet free, no snags
• Commands agreed with crew (Tacking! / Made!)
• Roll timing planned – who goes where when?
• Goal: minimal water time, not perfect sail geometry in irons
• VMG course after manoeuvre defined

Checklist: foiling gybe before training

• Wind strength checked – depower requirement clear
• Boom zone clear, duck position practised
• Mainsail eased before gybe (vang, outhaul)
• Call chain established (Gybe ho → Ready → Gybing → Made)
• Alternative plan for too much wind (pinching, no gybe)
• Crash recovery and capsize plan discussed

Related topics

• Tacking and Gybing
• Roll Tack and Roll Gybe
• What is Foiling
• IQFoil and Wingfoil in Competition
• Windward-Leeward Courses