Modular Ocean Living Platform — 40ft Container MVP
Small Waterline Area • Foil Legs • Solar-Powered • Community-Ready
The Triton-Class Seastead is a semi-mobile ocean platform designed for coastal and open-ocean living. Its elevated triangular living area sits atop three NACA 0030 foil-shaped legs that pierce waves with minimal disturbance—a small waterplane area concept inspired by semi-submersible oil platforms. The entire structural package is engineered to fit within a single standard 40-foot shipping container, enabling economical fabrication at a Chinese shipyard and shipping to the Caribbean for final assembly.
Key Design Drivers: Maximize solar-collecting roof area and interior living space while keeping all structural components container-friendly. The triangular planform provides inherent stability, aerodynamic efficiency when underway, and a natural layout for community connection (two seasteads can link bow-to-stern via a walkway).
| Parameter | Value | Notes |
|---|---|---|
| Triangle Frame – Port Side | 70 ft | Isosceles triangle, truss structure |
| Triangle Frame – Starboard Side | 70 ft | Mirror of port side |
| Triangle Frame – Back (Transom) | 35 ft | Base of isosceles triangle |
| Triangle Height (Bow to Transom) | ~67.8 ft | Calculated: √(70²−17.5²) |
| Interior Floor Area | ~1,186 sq ft | Entire triangle floor |
| Interior Ceiling Height | 7 ft | Within truss depth |
| Interior Volume | ~8,300 cu ft | Open-plan living |
| Truss Structural Depth | 7 ft | Floor-to-ceiling integrated truss |
| Roof Area (Solar) | ~1,186 sq ft | Triangular, near-full coverage |
| Leg Length (each of 3) | 19 ft | Vertical span of foil |
| Leg Chord | 10 ft | Fore-aft dimension of foil |
| Leg Max Thickness | 3 ft | NACA 0030 = 30% of chord |
| Leg Submersion (Design) | 50% = 9.5 ft | Draft at design displacement |
| Leg Cross-Sectional Area | ~20.4 sq ft | NACA 0030 at 10ft chord |
| Waterplane Area (Total, 3 legs) | ~61 sq ft | Small waterplane = wave-piercing |
| Total Displacement @50% | ~36,280 lbs | ~16.5 metric tonnes |
| Back Deck (each side of dinghy) | 5 ft wide × ~7 ft | Extends beyond transom |
| Dinghy Storage | 14 ft RIB, sideways | Centered on transom, wind-shielded |
The entire 1,186 sq ft triangle is an open-plan living area with 7 ft ceilings. The truss structure creates a clear span with no interior columns—all structural members are in the floor and ceiling planes. Large plexiglass windows wrap the perimeter, offering panoramic ocean views.
Suggested zones: Forward lounge (bow point), central galley & dining, sleeping quarters aft, bathroom with composting toilet, and a small navigation/office nook. The layout can be customized by the owner.
Natural light: With glass on all three sides and the triangular shape, sunlight tracks through the space all day. Roof hatches or skylights between solar panels add overhead light.
Comparable to a spacious 2-bedroom apartment.
| Item | Value |
|---|---|
| Roof Area | ~1,186 sq ft (triangular) |
| Usable Solar Area | ~1,050–1,100 sq ft |
| Panel Efficiency | 22–24% (high-efficiency mono) |
| Installed Capacity | ~20 kWpeak |
| Daily Production (Caribbean) | ~100–130 kWh/day |
| Annual Production | ~36,000–47,000 kWh |
| Panel Weight | ~2.8–3.5 lbs/sq ft (total ~3,300 lbs) |
With available payload capacity, the seastead can carry 5,000–8,000 lbs of LiFePO₄ batteries—approximately 330–530 kWh of storage. This provides 3–5 days of autonomy without sun, ample for propulsion, house loads, and the RIM drive thrusters.
Daily energy budget (estimated):
Each of the 3 legs is a vertical NACA 0030 symmetrical foil:
The NACA 0030 profile provides low hydrodynamic drag when moving forward, while the 3 ft thickness gives ample internal volume for buoyancy and structural framing. The leading edge is oriented forward on all three legs for consistent streamlining.
Each leg is a hollow marine aluminum shell with internal rib stiffeners:
Built-in ladder: The top half (above waterline) of the front (leading edge) of each leg has a recessed ladder—rungs welded into the foil surface for climbing from water to deck.
Per-leg weight: ~1,400–1,600 lbs
With only ~61 sq ft of total waterplane area across all three legs, the seastead largely ignores small chop and climbs large swells gently. This is the same principle used by semi-submersible oil platforms and SWATH (Small Waterplane Area Twin Hull) vessels. The penalty is reduced payload sensitivity—but the NACA foil shape recovers some efficiency by providing dynamic lift when underway, reducing wetted surface at speed.
RIM drives (permanent-magnet motors in the rim of the duct) have no shaft penetrations, no gearbox, and no exposed propeller—ideal for a seastead that may sit idle for long periods. They are inherently weed-resistant and safe for marine life.
A small electric actuator changes the elevator angle. The elevator, being aft of the main wing's pivot, creates a torque that rotates the entire stabilizer wing. This changes the main wing's angle of attack without needing a large, power-hungry actuator. The servo tab principle provides mechanical advantage—a small input yields a large control force.
All three stabilizers work together to dampen pitch and roll, especially at modest speeds (2–5 knots) where the foil legs alone provide less dynamic stability.
When the seastead needs to stay in one place for extended periods, three helical mooring screws are deployed—one near each leg. These screw anchors are driven into the seabed (works in sand, clay, and soft rock) and connected to the seasteed via synthetic tension legs (Dyneema or similar). The tension legs pull the seastead down slightly below its natural waterline, creating a pre-tensioned, nearly stationary platform.
This is the core engineering challenge. A standard 40-foot shipping container has internal dimensions of approximately 39.4 ft L × 7.7 ft W × 7.9 ft H (~2,390 cubic feet). Below is the breakdown of how all structural parts are packed.
| Component | Qty | Dimensions (each) | Container Strategy | Est. Volume |
|---|---|---|---|---|
| Triangle Side Chords (port & starboard) | 4 segments | 35 ft × ~8"×8" tube | Each 70ft side split into two 35ft bolted segments. Four 35ft chords lay along container length. | ~60 cu ft |
| Triangle Back Chord | 1–2 segments | 35 ft (or 2×17.5 ft) | Single 35ft piece or two shorter segments; lays with side chords. | ~15 cu ft |
| Truss Bracing (diagonals, verticals) | ~80–100 pieces | 2–8 ft lengths, tubes | Bundled and stacked in gaps between larger items. | ~80 cu ft |
| Floor & Roof Cross-Beams | ~40–50 pieces | 6–18 ft, aluminum I-beams | Nested together, strapped to container walls. | ~50 cu ft |
| Foil Legs (NACA 0030) | 3 legs | 19 ft L × 10 ft chord × 3 ft thick | Each leg split into 4 longitudinal skin panels (top, bottom, port, starboard) plus internal ribs. Panels nest: 12 panels @ ~19ft×2.5ft curved, stacked flat. Ribs (10ft×3ft) are cut in halves for flat-packing. | ~350 cu ft |
| Leg Internal Ribs (halved) | ~60–80 halves | ~5 ft × 1.5 ft × 3/16" | Flat-packed in crates between leg panels. | ~40 cu ft |
| Stabilizer Wings & Bodies | 3 units | 12 ft wingspan each | Wings detach; bodies are 6ft long. All nested diagonally. | ~90 cu ft |
| Back Deck Framing | 2 decks | 5 ft × 7 ft each | Flat aluminum grating/beams, stacked. | ~25 cu ft |
| RIM Drive Thruster Housings | 6 units | 1.5 ft dia × 1 ft | Nested in a crate. | ~15 cu ft |
| Fasteners, Brackets, Hardware | ~1 set | Various | Steel/aluminum crates,填补 gaps. | ~40 cu ft |
| TOTAL ESTIMATED VOLUME | ~765 cu ft | |||
| Container capacity | ~2,390 cu ft | |||
| Utilization | ~32% (ample room for packing materials & spare) |
| Item | Estimated Weight (lbs) | % of Displacement |
|---|---|---|
| Triangle Frame (chords, bracing, beams) | 6,500–7,500 | 18–21% |
| 3 Foil Legs (skins + ribs + ladders) | 4,200–4,800 | 12–13% |
| 3 Stabilizers (wings, bodies, actuators) | 1,200–1,500 | 3–4% |
| Back Decks (2) | 400–600 | 1–2% |
| RIM Drive Thrusters (6) | 1,500–1,800 | 4–5% |
| Solar Panels + Mounting | 2,800–3,500 | 8–10% |
| Plexiglass Windows | 1,000–1,500 | 3–4% |
| Interior Finishes (floor, walls, fixtures) | 2,000–3,000 | 6–8% |
| Batteries (LiFePO₄) | 5,000–8,000 | 14–22% |
| Dinghy + Outboard (RIB + HARMO) | 350–450 | 1% |
| Wiring, Electronics, Plumbing | 500–800 | 1–2% |
| Miscellaneous (anchors, lines, safety gear) | 500–1,000 | 1–3% |
| Subtotal (Dry Weight) | ~25,950–33,450 | 72–92% |
| People, Provisions, Cargo (payload) | 2,830–10,330 | 8–28% |
| TOTAL @ Design Waterline | ~36,280 lbs | 100% |
Payload flexibility: At the lighter end (~26,000 lbs dry), the seastead sits higher (~40–42% submersion), giving a softer ride and more reserve buoyancy. With full batteries and cargo (~33,000 lbs dry), it sits at the design 50% waterline. Maximum safe load (~60% submersion) allows up to ~43,500 lbs total, providing a generous safety margin.
| Metric | Estimate | Conditions |
|---|---|---|
| Cruising Speed | 3–5 knots | All 6 RIM thrusters @ 40–60% power |
| Max Speed | 6–7 knots | Full power, calm water |
| Range (battery only, no solar) | ~50–100 nm | At 4 knots, 500 kWh battery |
| Range (solar + battery) | ~300+ nm/week | Solar replenishes ~100 kWh/day |
| Wave Comfort (small chop <2 ft) | Nearly imperceptible | Small waterplane area |
| Wave Comfort (swells 4–8 ft) | Gentle, slow heave | Legs pierce waves; stabilizers active |
| Stability (intact) | Excellent | 3 widely-spaced buoyancy points |
| Wind Resistance (anchored) | Good | Low profile, aerodynamic triangle |
Order quantity: 10 seasteads (structural parts only)
Material: Marine-grade aluminum (5083-H321 / 6061-T6)
Process: Robotic plasma/laser cutting + robotic MIG welding
| Cost Category | Per Seastead (USD) | 10-Unit Total (USD) |
|---|---|---|
| Aluminum Raw Material (~15,000 lbs @ $3.50/lb) | $52,500 | $525,000 |
| CNC Cutting & Forming | $18,000–$24,000 | $180,000–$240,000 |
| Robotic Welding & Assembly | $25,000–$35,000 | $250,000–$350,000 |
| Surface Treatment (anodizing / epoxy coating) | $8,000–$12,000 | $80,000–$120,000 |
| Quality Control & Inspection | $6,000–$9,000 | $60,000–$90,000 |
| Packaging for Container Shipment | $4,000–$6,000 | $40,000–$60,000 |
| SUBTOTAL (Ex-Works, China) | $113,500–$138,500 | $1,135,000–$1,385,000 |
| Ocean Freight to Caribbean (per container) | $8,000–$12,000 | $80,000–$120,000 |
| TOTAL DELIVERED (Structural Parts) | ~$125,000–$150,000 | ~$1,250,000–$1,500,000 |
Marine Aluminum 5083-H321 for hull/leg skins and immersed components (excellent corrosion resistance in seawater). 6061-T6 for internal framing, truss members, and above-water structure (higher strength, good weldability).
| Feature | Specification |
|---|---|
| Living Space | 1,186 sq ft – open-plan, panoramic ocean views |
| Solar Power | ~20 kW peak – ~100–130 kWh/day in Caribbean sun |
| Displacement | ~36,000 lbs (~16.5 tonnes) at design waterline |
| Battery Capacity | 330–530 kWh (5,000–8,000 lbs LiFePO₄) |
| Propulsion | 6× RIM drive thrusters – electric, silent, 360° maneuverable |
| Stabilization | 3× servo-tab stabilizers + small waterplane legs |
| Anchoring | 3× helical mooring screws with tension legs |
| Container Fit | All structural parts in ONE 40ft container (~32% fill) |
| Structural Cost (10 units) | ~$125,000–$150,000 each, delivered Caribbean |
| Community | Two seasteads connect bow-to-stern with a walkway |
The Triton-Class seastead is designed to be the minimal viable product for ocean living—large enough to be comfortable, small enough to ship in one container, and engineered for the real challenges of the marine environment. Its foil-leg design, solar autonomy, and community-linking capability make it a practical foundation for the first true seasteading community.
Estimated Structural Cost: $125K–$150K per seastead 10-Unit Order: ~$1.25M–$1.5M total