Design & Technology · Structure & materials
Light enough
to fly
Carbon hulls, carbon deck, carbon fittings. And a structure stiff enough to carry the loads of a foil that lifts twenty tonnes.
“The lightest equipment, the lightest structure. The toilet is carbon.”
Construction
Carbon
sandwich
Hulls and superstructure are carbon fibre laminated over foam and Nomex honeycomb cores. It is the same approach used for America’s Cup and Grand Prix offshore yachts.
A foiling yacht concentrates huge loads into small areas: the foil case, the rudder bearings, the chainplates and the beams that join the hulls. The laminate is engineered around those load paths, adding material only where it carries force and taking it away everywhere else.
Persico Marine built dedicated molds for every major structure, so the finished parts match the design geometry closely enough for the flight-control system, once it is programmed, to trust them.
Engineering
Every load
mapped
The whole yacht was modelled in Finite Element Analysis. The colours show stress across the composite structure, from deep blue where it is lightly loaded through green to red where the loads concentrate.
“We used Finite Element Analysis to map stress and strain distributions across the composite laminate structure, informing everything from laminate schedules and bulkhead placement to the reinforcement of foil cases and the optimisation of load paths.” Ferdinand van West, Seahorse, July 2025.
Finish
The colour
of the original
The lime-green hull with its magenta stripe carries the identity of the first Extreme H2O, first multihull to finish the 2015 Transpac. Under the paint, it is a completely new structure.
Construction & class
- Hull
- Carbon
- Foam & Nomex sandwich
- Classification
- ISO Cat. A
- ISO 12215-7 · highest category
- Propulsion
- 2 × 35 kW
- Electric · Torqeedo
- Racing displacement
- ≈ 21.5 t
- As built
Systems
Hydraulics
where it counts
Four hydraulic winches handle the sheets, each built to hold around twelve tonnes. Hydraulic rams rake the foil cases. Two 35 kW electric motors move her silently in and out of harbour.
Full specificationsPrivate enquiries
PB72 is in sea trials. Partnerships, racing programs, experiences and charter are discussed personally with our team.
Extreme H2O · Foiling ocean catamaran · Technical specification
PB72 specifications
Morrelli & Melvin · GA PB72_001 Rev A · Persico Marine build spec
- Length overall
- 21.95 m
- 72.0 ft
- Beam
- 9.50 m
- 31.2 ft
- Racing displacement
- ≈ 21.5 t
- As built · VPP targets at 20.3 t
- Mast
- 32.33 m
- Air draft 37 m
- Upwind sail area
- 420 m²
- Main 224 + J1 196
- Fastest upwind
- J3 + main
- Full main 224 + J3 115 m²
- Fastest downwind
- MHO + main
- Full main 224 + MHO 358 m²
- Predicted top speed
- 40+ kn
- VPP
Principal dimensions
- Length overall
- 21.95 m72.0 ft
- Length incl. longeron
- 24.10 m79.1 ft
- Length waterline
- 21.45 m70.4 ft
- Beam overall
- 9.50 m31.2 ft
- Hull centreline spacing
- 7.52 m24.7 ft
- Freeboard
- 2.07 m6.8 ft
- Draft, boards down
- 5.31 m17.4 ft
- Draft, foils raised
- 0.65 m2.1 ft
- Air draft
- 37.00 m121.4 ft
Displacement & stability
- Light displacement
- ≈ 21,000 kgAs built · design 20,500 kg
- Racing displacement
- ≈ 21,500 kgAs built · as sailed in sea trials
- VPP target displacement
- 20,280 kgDesign racing weight used for the polar targets
- Design displacement (mLDC)
- 23,047 kgMaximum load condition
- Max total load (ISO 8666)
- 22,518 kg
- Steady-state sailing RM
- 830 kNmAt full-payload displacement
- Max dynamic RM
- 1,340 kNmRace mode, RMFoil deployed
Rig
- Mast tube length
- 32.33 m106.1 ft
- Mast design rake
- 4°
- P
- 31.285 mReefs: 26.604 · 21.970 · 14.190 m
- E
- 9.678 m
- I (1 · 2 · 3)
- 33.470 · 32.775 · 30.900 m
- I headstay (5 · 6)
- 28.050 · 25.720 m
- J (1 · 2 · 3)
- 12.180 · 11.730 · 10.980 m
- J headstay (5 · 6)
- 8.744 · 8.072 m
- BAD · HBI
- 1.906 · 2.019 m
Sail areas
- Mainsail, full
- 224 m²Reefs: 183 · 144 · 76.8 m²
- J0
- 219 m²
- J1
- 196 m²
- J3
- 115 m²
- J4 / staysail
- 87.3 m²
- FRO
- 304 m²
- MHO
- 358 m²
- A1
- 365 m²
- Fastest upwind setup
- J3 + full mainJ1 in marginal upwind conditions, 13–14 kn: partial foiling
- Fastest downwind setup
- MHO + full main
Foils & flight control
- Righting-moment foil
- ≈ 16 × 3 ftCurved carbon foil in a hydraulically raked case
- Daggerboards
- Centreline, per hullIndependent of the lifting foil
- Rudders
- Raking, T-foilConical titanium bearings · ≈ 6 ft T-foils
- Flight control
- Designed for fly-by-wireFoil lift and rudder-elevator control; programmed after sea trials
Construction & class
- Hull
- Carbon fibreFoam & Nomex sandwich
- Superstructure
- Carbon fibreFoam & Nomex sandwich
- Classification
- ISO 12215-7 Cat. ASER1 multihull · highest category, sport boat
- Propulsion
- 2 × 35 kW electricTorqeedo
Rig & deck hardware
- Mast
- Carbon rotating wing mastSupplied by SSNZ · single spreader, double diamond, running backstays
- Primary winches
- 4 × Harken 1125.3
- Secondary winches
- 2 × Harken 65.3 ST
- Windlass
- Lewmar V6 hydraulic
Propulsion & power
- Main engines
- 2 × Torqeedo electric25 kW continuous · 35 kW max each
- Drive
- Shaft driveStrut and P-bracket · Gori GP20 folding propellers
- Motoring speed
- 9.2 kn max7.5 kn cruise (estimated)
- Generators
- 2 × 20 kW Fischer Panda
- Propulsion battery
- 40 kWh lithium-ionBMW i3 cells
- Solar
- 2 kWPanels on the coachroof
- Electrical
- 120 V and 240 V AC400 V DC charging & hydraulic bus · 24 V domestic · Empirbus digital switching
Tankage
- Fuel
- 2 × 550 L
- Fresh water
- 2 × 450 LPlus 70 L drinking water
- Watermaker
- Schenker Modular Zen 50
- Black water
- 2 × 220 L
Comfort & systems
- Air conditioning
- 64,000 BTU/hTermodinamica
- Galley
- Gaggenau hobsPizza oven · Miele microwave · Miele coffee machine
- Refrigeration
- 3 × 172 L fridgesPlus Frigonautica freezer
- Navigation
- B&G / Simrad
- Communications
- VHF · 5G · SatcomSatellite broadband
- Steering
- Outside helms + inside helmFly-by-wire steering at the inside helm station
Performance
- Predicted top speed
- 40+ knPolar peak 40.7 kn
- Foiling onset
- 11–13 kn TWSDepending on sail set
- Upwind, 13 kn of wind
- ≈ 24 kn
- Downwind, 14 kn of wind
- ≈ 31 kn
- Crew
- 4 per watchTo sail her fast; two watches for round-the-clock ocean racing
Velocity prediction program, partially validated in sea trials.
Design & build
- Naval architecture
- Morrelli & MelvinNewport Beach, California
- Lead designer
- Ferdinand van WestThen at Morrelli & Melvin; now Van West Naval Architecture
- Interior architecture
- Design Unlimited
- Builder
- Persico MarineItaly
- Flight control
- Team New Zealand engineers
- General arrangement
- PB72_001 · Rev A6 August 2022
Figures from the Morrelli & Melvin general arrangement (PB72_001, Rev A, August 2022) and the Persico Marine build specification. Displacements are approximate as-built figures from Ferdinand van West (2026); righting moments are design estimates; performance figures are VPP predictions, calculated at the 20,280 kg design racing displacement.
Every cell is a predicted boat speed from the velocity prediction program. The circled cells are the targets PB72 has already hit in her first sea trials, with the foils still trimmed by hand. Each one came in on target.
| Wind angleTrue wind (kn) | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 18 | 20 | 22 | 24 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 45° | 7.6 | 8.4 | 9.1 | 9.8 | 10.4 | 11.3 | 12.6 | 13.6 | 14.4 | 15.1 | 16.0 | 17.4 | 20.5 | 23.4 | 24.0 | 23.7 |
| 50° | 8.0 | 8.9 | 9.7 | 10.5 | 11.2 | 12.8 | 14.3 | 15.1 | 16.3 | 17.6 | 19.5 | 21.6 | 27.1 | 27.5 | 27.0 | 26.5 |
| 55° | 8.4 | 9.3 | 10.2 | 11.2 | 12.2 | 14.2 | 15.7 | 17.0 | 18.8 | 20.8 | 23.4 | 27.6 | 30.1 | 30.2 | 29.5 | 28.9 |
| 60° | 8.8 | 9.7 | 10.7 | 11.8 | 13.2 | 15.3 | 17.1 | 19.3 | 21.5 | 26.1 | 28.6 | 30.2 | 32.4 | 32.3 | 31.6 | 30.9 |
| 65° | 9.1 | 10.1 | 11.2 | 12.3 | 14.3 | 16.4 | 19.1 | 21.5 | 26.1 | 29.0 | 30.8 | 32.2 | 34.3 | 34.2 | 33.4 | 32.4 |
| 70° | 9.3 | 10.4 | 11.5 | 12.7 | 14.9 | 17.9 | 20.9 | 24.1 | 28.6 | 30.8 | 32.4 | 33.8 | 35.8 | 35.7 | 34.8 | 32.3 |
| 75° | 9.5 | 10.6 | 11.8 | 13.1 | 15.4 | 19.4 | 22.6 | 27.3 | 30.2 | 32.2 | 33.7 | 35.1 | 37.1 | 37.1 | 36.2 | 34.0 |
| 80° | 9.7 | 11.0 | 12.3 | 13.9 | 15.8 | 20.6 | 25.1 | 28.7 | 31.4 | 33.2 | 34.7 | 36.1 | 38.1 | 38.2 | 37.3 | 36.2 |
| 85° | 9.8 | 11.2 | 12.6 | 14.2 | 16.2 | 21.3 | 26.9 | 29.8 | 32.2 | 34.0 | 35.5 | 36.9 | 39.0 | 39.1 | 38.3 | 37.5 |
| 90° | 9.9 | 11.3 | 12.7 | 14.4 | 16.4 | 21.5 | 27.7 | 31.5 | 33.5 | 35.1 | 36.3 | 37.5 | 39.6 | 39.8 | 39.1 | 38.7 |
| 95° | 9.9 | 11.3 | 12.8 | 14.4 | 16.5 | 21.0 | 28.7 | 31.7 | 33.9 | 35.5 | 36.8 | 37.9 | 40.0 | 40.3 | 39.8 | 39.5 |
| 100° | 9.9 | 11.3 | 12.7 | 14.2 | 16.3 | 22.3 | 28.8 | 31.7 | 34.2 | 35.8 | 37.0 | 38.1 | 40.3 | 40.6 | 40.3 | 40.0 |
| 105° | 9.8 | 11.1 | 12.5 | 14.0 | 15.7 | 21.0 | 28.3 | 31.4 | 34.0 | 35.8 | 37.1 | 38.2 | 40.3 | 40.7 | 40.5 | 40.3 |
| 110° | 9.7 | 10.9 | 12.2 | 13.6 | 15.1 | 17.7 | 26.8 | 31.0 | 33.3 | 35.5 | 37.0 | 38.2 | 40.2 | 40.7 | 40.6 | 40.4 |
| 115° | 9.5 | 10.6 | 11.8 | 13.1 | 14.5 | 16.5 | 19.9 | 30.0 | 32.6 | 34.8 | 36.6 | 37.9 | 40.0 | 40.3 | 40.4 | 40.1 |
| 120° | 9.2 | 10.3 | 11.4 | 12.5 | 13.7 | 14.9 | 17.4 | 25.8 | 31.8 | 34.0 | 35.6 | 37.4 | 39.6 | 40.0 | 40.0 | 39.6 |
| 125° | 8.9 | 9.9 | 10.8 | 11.6 | 12.4 | 13.5 | 14.7 | 16.3 | 29.7 | 32.9 | 34.9 | 36.4 | 39.0 | 39.6 | 39.6 | 39.1 |
| 130° | 8.5 | 9.4 | 10.0 | 10.8 | 11.9 | 13.1 | 14.3 | 15.5 | 17.1 | 18.0 | 33.4 | 35.4 | 38.1 | 38.9 | 39.1 | 38.6 |
| 135° | 8.2 | 8.7 | 9.5 | 10.5 | 11.5 | 12.6 | 13.7 | 14.8 | 16.2 | 17.3 | 18.4 | 20.0 | 37.0 | 38.0 | 38.2 | 37.7 |
| 140° | 7.6 | 8.2 | 9.1 | 9.9 | 10.9 | 11.9 | 12.9 | 14.0 | 15.2 | 16.4 | 17.7 | 19.1 | 22.1 | 35.4 | 30.7 | 35.0 |
Predicted speeds from the velocity prediction program. Sea-trial targets achieved with manual foil trim; the automatic flight-control system comes online after calibration.
- VPP targets calculated at
- 20,280 kg
- Design racing displacement
- Sea trials sailed at
- ≈ 21,500 kg
- As-built racing displacement
Every circled target was reached with the boat about 1.2 tonnes heavier than the weight the predictions assume.