A two‑person, solar‑electric, three‑foil seastead scaled from the 44′ reference design so that every structural part ships in one 40′ High Cube container for assembly at any yard near the target market.
The reference 44′ design is excellent but sized for a 45′ container. The MVP scales the whole platform by 0.84× so the three wall panels remain single pieces inside a standard 40′ High Cube (interior 39.5′ × 7.7′ × 8.9′, payload ~58,000 lb). Everything else follows from that one constraint:
This hits all six of your stated MVP requirements while cutting displacement to ~74% and interior area to ~71% of the 44′ design — which is exactly where the cost of the first units drops the fastest.
The single hard constraint is the wall panels. In the 44′ design each wall is one 44′ piece — it fits a 45′ container but not a 40′. Scaling so the wall is 37.0′ leaves 2.5′ of length margin for end protection and lifting fixtures, and everything else was re‑derived from it:
| Parameter | 44′ Reference | Triton‑37 MVP | Ratio |
|---|---|---|---|
| Triangle side | 44.0 ft | 37.0 ft | 0.84 |
| Interior floor area | 838 ft² | 593 ft² | 0.71 |
| Leg span / chord | 21.5 / 8.5 ft | 18.0 / 7.0 ft | 0.84 / 0.82 |
| Foil max thickness | 2.98 ft | 2.45 ft | 0.82 |
| Static buoyancy (half‑immersed) | ~27,500 lb | ~20,300 lb | 0.74 |
| Mid‑span beam triangle | 22 ft | 18.5 ft | 0.84 |
| Battery (25% of displacement) | ~330 kWh | ~236 kWh | 0.72 |
| Item | Specification |
|---|---|
| Platform | Equilateral triangle frame/wall, 37.0′ per side; wall clear height 6.5′; wall panels ~7″ thick aluminum (5083/6061), insulated option |
| Floor / ceiling | Structural mid‑span beams connect wall midpoints (inner triangle 18.5′ per side); remaining floor & ceiling in ~4′×4′ bolt‑in panels (~80 pcs + edge fillers) |
| Walkway | 3.0′ wide aluminum grating, bolt‑on, 1.0′ above wall base, diagonal braces below; full perimeter except stern dinghy notch; 42″ railing |
| Doors | Two 30″ doors on stern wall, 2.0′ in from each corner |
| Legs | 3 × span 18.0′, chord 7.0′, NACA 0035 (max thickness 2.45′), trailing edge truncated last 0.4′; thickest point centered 1.4′ inside the triangle, as close to each corner as possible; all three parallel, blunt (leading) edge forward |
| Immersion | 50% of leg length at rated condition; ~43% at design load → floor ~10′ above waterline |
| Compartments | Each leg: 4 watertight compartments, no through‑hulls; wiring exits via conduit welded to trailing edge |
| Ladders | Built into upper (dry) half of the forward face of each leg |
| Heave plates | 2 bolt‑on plates per leg (~4′×4′) on the lower half; optional deeper pair |
| Thrusters | 6 × rim‑driven, 1.3–1.5′ dia., 5 kW each, fixed forward orientation, one per side of each leg ~1.8′ above leg bottom; differential‑thrust steering; counter‑rotating spin for station‑keeping twist |
| Battery | ~236 kWh LiFePO₄ (~78 kWh per leg, ~1,330 lb per leg) in lower‑leg compartments; 48 V architecture |
| Power electronics | Per leg: MPPT charge controller + inverter/charger → triple‑redundant power; each leg’s thruster pair fed only from its own leg |
| Solar | 8.6 kW rooftop (18 × 480 W), walkway‑clear margins |
| Water | 20 GPH DC watermaker; 80 gal tank; roof rain‑catchment with first‑flush diverter (bonus in Caribbean squalls) |
| Tender | 14′ RIB (ships deflated) + Yamaha HARMO electric outboard; hung sideways on two rope davits astern, wind‑shadowed by the house |
| Mooring | Pair of helical screws per corner with motorized drive sled between; 3′ pull‑down tension‑leg mode for Caribbean anchorages |
| Masses | Lightship ~16,750 lb; design loaded 17,500 lb; reserve to static buoyancy ~2,800 lb (14%) |
| Shipping | All primary structure in one 40′ HC; small companion crate contingency for tender/mooring (§4) |
| Load | kWh/day |
|---|---|
| Fridge/freezer (6–7 ft³ compressor) | 1.4 |
| Watermaker (16 gal) | 0.9 |
| Induction cooking | 1.2 |
| Lighting (all LED) | 0.3 |
| Electronics / comms / nav | 0.5 |
| Ventilation fans + misc | 0.7 |
| Total house | ~5.0 |
| Solar yield (Caribbean, 5.5 sun‑h × 8.6 kW × 0.8) | ~30–38 |
6–8× surplus at anchor. Surplus converts to ~3–4 hours of extra cruising per day in sunshine — effectively extending range by 30–50% whenever the sun is up.
| Mode | Power | Speed | Endurance (236 kWh, 80% DoD) |
|---|---|---|---|
| Eco | 4 kW | ~3.8 kn | ~190 nm |
| Cruise | 8 kW | ~4.9 kn | ~118 nm |
| Transit | 16 kW | ~6.1 kn | ~59 nm |
| Sprint (all 6) | 28 kW | ~7.2 kn | ~34 nm |
Plus the non‑negotiables: composting head, 42″ railings, EPIRB, 4‑person liferaft canister, fire extinguishers, bilge/compartment flood sensors, AIS‑B, LED nav lights, and per‑leg bilge pumps (gravity‑assisted where possible).
| # | Group | lb |
|---|---|---|
| 1 | Structure: walls, floors, ceiling, beams, corner nodes, legs, walkway, railings, doors, ladders | 7,600 |
| 2 | Heave plates (6) | 450 |
| 3 | Rim thrusters (6) + conduits | 600 |
| 4 | Batteries ~236 kWh LFP + BMS | 4,000 |
| 5 | Solar 8.6 kW, 3× inverter/charger, MPPT, wiring | 1,300 |
| 6 | Plumbing: watermaker, tank, pumps, head | 350 |
| 7 | Galley, fridge, furnishings, berth | 850 |
| 8 | Tender + HARMO + davits | 600 |
| 9 | Mooring kit (6 screws, sleds, tackle) | 700 |
| 10 | Safety, nav, paint, anodes, misc | 300 |
| Lightship | 16,750 | |
| 11 | Crew, water, stores | 750 |
| Design loaded displacement | 17,500 | |
| — | Static buoyancy at half‑immersion (3 legs) | ~20,300 |
| — | Reserve (freeboard margin) | ~2,800 (14%) |
Battery check: 78 kWh per leg ≈ 35–47 ft³ of pack — fits the lower‑leg compartment volume with the foil’s ~100 ft³ of submerged internal space at ~40% packing efficiency. Custom prismatic modules assumed.
| Feature | Status | Notes |
|---|---|---|
| Solar / battery / inverter, triple‑redundant | IN | Core product |
| Sleeping for 2 (+guest conversion) | IN | |
| Fridge/freezer, induction galley | IN | |
| Watermaker + rain catchment | IN | Single watermaker (redundancy = catchment + jerry cans) |
| Stability ≥ yacht at one desk | IN | Waterplane design + tension‑leg parking |
| Food/clothes storage | IN | ~60 ft³ + leg lockers |
| 6× rim thrusters, differential steering | IN | Fallback: conventional pod motors if supplier slips |
| Tender + electric outboard + rope davits | IN | |
| Helical‑screw tension‑leg kit | IN | Hardpoints standard; kit itself deferrable per customer |
| Inter‑seastead walkway hardpoints | IN | Standardized stern coupling interface |
| Active two‑boat motion‑sync control | PHASE 2 | Computers and thruster API designed for it now |
| HVAC / heating | OUT | Insulation + fans; Caribbean climate |
| Second watermaker, washer, dive locker, lux finishes | OUT | Series‑2 options |
| Auto‑deploy mooring robotics | OUT | Manual‑assist in MVP |
Effort: ~600–800 labor‑hours, 3–4 workers, 4–6 weeks, one 10–20 t mobile crane. Yard requirement: paved apron, welding capability, forklift, crane — no slipway needed (launch by crane like a catamaran).
| Line | Low | High |
|---|---|---|
| Engineering, lofting, FEA, model tests (one‑time) | 120,000 | 200,000 |
| Aluminum fabrication, China (structure + legs + nodes) | 140,000 | 190,000 |
| Rim thrusters ×6 | 18,000 | 30,000 |
| Battery 236 kWh LFP + BMS | 55,000 | 75,000 |
| Solar + inverters + wiring | 12,000 | 18,000 |
| Watermaker, galley, furnishings, head | 8,000 | 12,000 |
| Tender + HARMO | 11,000 | 15,000 |
| Mooring kit | 7,000 | 10,000 |
| Shipping (40′ HC + companion crate) | 6,000 | 9,000 |
| Yard assembly labor | 30,000 | 65,000 |
| Contingency 15% | 60,000 | 95,000 |
| Total first unit (incl. one‑time eng.) | ~470,000 | ~720,000 |
| Recurring hardware at ~10 units | ~260,000 | ~340,000 |
Ballpark figures for planning only — quotes will move these substantially. The biggest cost levers are thruster sourcing and battery cell pricing.
| Risk | Mitigation |
|---|---|
| Container Tetris doesn’t close in practice | Plywood mock‑up before metal is cut; companion crate held as fallback; wall thickness is the tuning knob |
| Rim‑drive supplier/quality | Dual‑source RFQs now; mechanical envelope accepts conventional pod motors as drop‑in fallback |
| Fatigue at leg‑to‑node joints | FEA + full‑scale static test; forged/machined nodes; bolted (inspectable) rather than welded joint at deck interface |
| Corrosion (Al legs, mixed metals, warm sea) | 5083 plate, isolated fasteners, oversized sacrificial anodes, ablative antifoul on lower halves only |
| Battery mass low in legs → impact damage | Watertight compartments, crash‑bulkhead forward, fendered leg noses, insurance‑grade BMS |
| Reserve buoyancy thinner than 44′ design | 14% reserve held; chord 7.0→7.2′ upgrade path adds ~2,800 lb if ever needed |
| Regulatory/flag uncertainty | Operate initially as private pleasure vessel; engage flag state early; keep weight/CE‑style documentation from day one |