The Build
From concept to start line
A foiling Moth is one of sailing's most technically demanding one-design classes. It rewards precision engineering and punishes shortcuts. That is why we chose it.
The Vessel
A foiling Moth
The International Moth is a single-handed sailing dinghy that flies above the water on hydrofoils. At full flight, only the foils and rudder touch the water — the hull is airborne.
The SuMoth Challenge adds a critical constraint: every material decision, structural choice, and fabrication method must meet measurable sustainability standards. That constraint does not reduce the engineering — it amplifies it.
Target Specifications
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Foiling Moth reference photo
A foiling Moth at full flight. Hull airborne, hydrofoils supporting full vessel weight.
Engineering Systems
Five integrated systems
Hull Structure
Bio-composite construction. Sustainable reinforcement fibres with bio-based epoxy resin systems. Weight-optimized for foiling performance.
Hydrofoils
CFD-optimized profiles using OpenFOAM. Lift, drag, and cavitation analysis. Composite construction with precision surface finish.
Rig & Sail
Integrated sail control systems. Optimized for competitive performance within sustainability constraints. Carbon and natural fibre hybrid.
Control Systems
Wand-based ride height control. Flap mechanisms for foil angle adjustment. Mechanical systems designed for reliability.
Materials
Full lifecycle assessment on every material. Bio-based resins, natural fibre reinforcements, recycled core materials. Every choice measured.
Project Timeline
Full roadmap
CFD — Hull
May – Jun 14, 2026
Hull shape validated via HPC-powered CFD simulations.
Computational fluid dynamics analysis to validate and freeze the hull shape. Meshing, simulation, and optimization runs on the 32-core cluster, with final drag and lift coefficients reviewed against performance targets.
- Preliminary meshing, simulation, and optimization complete
- CFD runs on 32-core HPC cluster
- Hull shape validated and version-controlled
- Results reviewed and accepted by team leads — Gate 1
CFD — Foil & Wings
May – Aug 16, 2026
Foil and wing geometries optimised across three design iterations.
Parallel CFD campaign to validate foil and wing shapes. Runs from preliminary design through three iterative stages, culminating in validated mainfoil, rudderfoil, and wing geometry ready for structural analysis inputs.
- Preliminary foil and wing design and meshing
- Secondary design following 32-core optimization run
- Final foil and wing geometry validated
- Lift, drag, and moment coefficients reviewed against VPP targets — Gate 3
System Design
May – Jun 28, 2026
Full-boat CAD assembly ready for sponsors and analysis inputs.
Full CAD model of the complete boat system, ready to present to sponsors and begin structural analysis. Covers gantry, wing, mast post, and moth reference measurements, with an assembly clash check and sponsor-ready render.
- Moth reference measurements collected (Biecker, Mach 2, Exocet, Wasp)
- Gantry, wing, and mast post CAD models complete
- Full top-level assembly with clash check
- Sponsor-ready render produced — Gate 2
Structural Analysis
Jun 14 – Oct 2026
FEA validates composites layup across all primary structures.
Material selection, FEA, and layup schedule definition for all primary structural members. Lab coupon testing runs in parallel. Gate 4 must pass before any mold construction begins.
- Internal hull and deck structure designed
- FEA completed for hull, foil, gantry, and wings
- Material selection finalized — resin, fibre, core
- Fiber direction plan and layup schedule approved — Gate 4
Manufacturing Prep
Mid-Sep – Dec 2026
All molds designed and built before the winter exam period.
Design and construction of all molds, and definition of fabrication processes for wings and gantry. All mold work must complete before winter exams. No mold construction begins until Gate 4 passes.
- Hull and foil mold designs complete
- Hull mold construction complete
- Foil mold construction complete
- Wing and gantry fabrication processes defined
Purchasing & Design Review
Nov 15 – Dec 13, 2026
Design frozen; full BoM ordered before year-end.
Design is locked. All major purchases are approved and ordered before the exam period. Full Bill of Materials with supplier quotes, budget review, and team role confirmation. No design changes after this gate without formal change control.
- Full Bill of Materials with supplier quotes produced
- All large material purchases approved and ordered
- Risk register reviewed — all high risks have mitigation owners
- S1 Report at least 50% drafted — Gate 5
Manufacturing
Jan – Apr 2027
Hull, foils, wing panels, and gantry fully fabricated.
Full composite fabrication of the boat: hull layup, foil fabrication, wing panel construction, and gantry assembly. All work proceeds from frozen designs and approved materials.
- Hull composite layup from mold
- Mainfoil and rudderfoil fabricated
- Rigid wing panels manufactured
- Rudder gantry assembled — Gate 6
Validation
Apr – May 2027
Structural and compliance checks before first water entry.
Structural integrity and dimensional checks on all manufactured components. IMCA class compliance verified and measured. Flight control system tested on land. Faculty Advisor safety sign-off required before water entry.
- Structural integrity checks on all primary components
- IMCA dimensional compliance verified
- Flight control system (wand, flap linkage) functional on land
- Faculty Advisor safety sign-off — Gate 7
Testing
May – Jul 2027
Three qualifying GPS runs submitted to SuMoth Challenge.
On-water testing begins when the lake is free (~May). GPS performance trials for SuMoth S2 submission. At least three qualifying runs completed per SMC course specifications.
- First on-water trials
- Minimum 3 qualifying GPS runs completed
- GPS data submitted to SMC organisation
- Performance Showcasing video submitted — Gate 8
Documentation
May 2026 – Aug 2027
Continuous reporting across all SuMoth submission stages.
Continuous documentation throughout the full project lifecycle supporting SuMoth Challenge submissions. Covers Blog Posts A, B, and C, the S1 Design Report, MS360 LCA Report, S2 Manufacturing Report, and S3 Fleet Racing at Lake Garda.
- Blog Posts A & B (Aug and Nov 2026)
- S1 Design Report + LCA Report (Jan 2027)
- S2 Manufacturing Report (Jun 2027)
- S3 Fleet Racing — Lake Garda (Jul 2027)
Design Process
Every decision measured
Our design process integrates computational fluid dynamics (CFD), finite element analysis (FEA), and material lifecycle assessment at every stage. OpenFOAM provides our hydrodynamic simulation backbone. Ansys is used for structural analysis. Everything is planned and tested before implementation.
Material decisions are not decorative — each candidate undergoes mechanical testing, lifecycle assessment, and performance benchmarking against conventional alternatives. The trade-off data is public. The reasoning is documented.