Seastead Design Analysis Report

45ft High-Cube Containerizable Trimaran Seastead - MVP for 2 Persons

Disclaimer: This is a preliminary engineering estimation based on the provided concept description. It is intended for concept validation and high-level planning, not for construction. Hydrodynamic coefficients (Cd, Cl, Added Mass, Damping) are estimated using strip theory approximations and empirical formulas for NACA 0035 foils. Structural weights assume Marine Grade Aluminum (5083/6061) welded construction. Real-world values require CFD, FEA, and Naval Architecture verification. "Containerizable" implies knock-down kit; final assembly requires a shipyard.

1. Core Design Parameters & Geometry

Parameter	Value	Notes
Container Internal Dim (LxWxH)	44.6 ft x 7.7 ft x 8.9 ft	High Cube 45ft
Max Payload Weight	62,000 lbs	Container rating
Target Displacement (Design Waterline)	27,500 lbs (12,474 kg)	Saltwater ~64 lbs/ft³ -> 430 ft³ submerged volume
Triangle Frame (Equilateral)	Side: 44 ft, Height: 7 ft (Floor-Ceiling)	Living Area ~836 ft²
Walkway	3 ft wide, 1 ft above keel bottom	Aluminum Grating
Legs (x3)	NACA 0035, L=21.5 ft, Chord=8.5 ft (t=2.975 ft)	Trailing edge cut 0.5 ft for container height (8.0 ft max)
Leg Submergence	50% (10.75 ft draft / 10.75 ft freeboard on leg)	Waterline at mid-chord thickness
Leg Volume (Total x3)	~1,150 ft³ (Theoretical 100%)	50% Submerged = 575 ft³ = 36,800 lbs Buoyancy. Target 27,500 lbs implies ~37% submergence or smaller foil. Analysis assumes target 27,500 lbs displacement.
Waterplane Area (WPA) @ WL	~72 ft² (3 legs x 2.975 ft thick x 8.5 ft chord? No, WPA = 3 * Chord * 1ft? No.)	WPA = 3 legs * (Chord at WL) * Length_wl. At 50% submergence, WL cuts max thickness. Waterplane beam ~2.975 ft. WPA = 3 * 2.975 * 21.5 = 191 ft². Correction: User says "1 ft change = 1/7 buoyancy". 27,500/7 = 3,900 lbs/ft. 3,900/64 = 61 ft² WPA. This implies legs are farther apart or chord at WL is smaller. We will use WPA = 65 ft² for hydrostatics.
BM (Metacentric Radius)	I / V = (3 * (22sin60)^2 65/3? ) / 430	Approx BM ~ 150 ft. KB ~ 5 ft. KG ~ 10 ft (Batteries low). GM ~ 145 ft. Extremely Stiff.
Battery Allocation	25% Displacement = 6,875 lbs	LiFePO4 Pack Level ~35 Wh/lb
Solar Roof Area	~836 ft² (Triangle) + ~300 ft² (Walkway roof?)	Assume 1,000 ft² usable @ 18.6 W/ft² = 18.6 kWp

2. Energy System: Solar, Batteries & Power Budget

2.1 Solar Production

Item	Value
Installed Peak Power (kWp)	18.6 kWp (1,000 ft² @ 18.6 W/ft², 20% eff, packing factor 0.9)
Caribbean Average Peak Sun Hours	5.0 - 5.5 hrs/day
Average Daily Production	~93 - 102 kWh/day
Average Continuous Power (24/7)	3,900 - 4,250 Watts

2.2 Battery Bank (LiFePO4)

Parameter	Value
Weight Budget	6,875 lbs (25% Disp)
Specific Energy (Pack Level)	35 Wh/lb (Conservative, incl. BMS, racking, fire suppression)
Total Capacity	~240 kWh
Usable Capacity (80% DoD)	192 kWh
Cost @ $90/kWh (Cell) -> ~$130/kWh Pack	$31,200
Weight per Leg	2,290 lbs (Low in foil, excellent for KG)

2.3 Average Daily Load Profile (MVP - 2 Persons)

Load	Avg Watts	Daily kWh	Notes
AC (1 unit, 50% duty, tropics)	600 W	14.4	12k BTU Inverter Mini-split
Water Maker (2x, 1 running)	400 W	9.6	60 GPD Spectra type
Refrigeration/Freezer	100 W	2.4	High eff marine
Electronics/Starlink/Comms	150 W	3.6	2x Starlink, laptops, phones
Lighting/Ventilation/Pumps	100 W	2.4
Incinerating Toilet (Cycles)	150 W	3.6	Avg 1.5 hrs/day @ 1.5kW
Cooking (Induction/Microwave)	200 W	4.8	Avg 30 min high power
Hotel Load Total	~1,700 W	~40.8 kWh
Propulsion Average (24/7)	2,200 W	52.8 kWh	Available from Solar Surplus
Total Average Draw	~3,900 W	~93.6 kWh

Result: Solar Production (~98 kWh) ≈ Total Daily Demand (~94 kWh). Net Zero Energy achievable on average day. Battery (192 kWh usable) provides 2+ days autonomy for cloudy weather.

3. Wind Drag, Station Keeping & Sailing Performance

3.1 Windage Area Calculation

House Frontal Area: 44 ft (base) x 7 ft (wall) x 0.5 (triangle) = 154 ft². + Roof pitch? ~180 ft².
Legs Above Water (3 x 10.75 ft x 2.975 ft): ~96 ft².
Walkway/Railing/Solar Mounts: ~50 ft².
Total Effective Wind Area (A_w): ~326 ft² (30 m²). Cd ~ 1.2 (House) / 1.0 (Foils). Weighted Cd ~ 1.1.

3.2 Station Keeping Power (Head to Wind)

Drag Force F = 0.5 * rho_air * Cd * A * V². Prop Power = F * V / eta_prop. Eta_prop (RIM) ~ 0.65.

Wind Speed	Drag Force (lbs)	Thrust Required (lbs)	Shaft Power (kW)	Battery Drain (kWh/hr)
20 mph (8.9 m/s)	280	280	1.1	1.1
30 mph (13.4 m/s)	630	630	3.8	3.8
40 mph (17.9 m/s)	1,120	1,120	9.0	9.0
50 mph (22.3 m/s)	1,750	1,750	17.5	17.5

Analysis: At 30 mph, station keeping uses ~3.8 kW (91 kWh/day) – nearly all solar production. At 40+ mph, battery drain is severe (17.5 kW). Do not plan to station-keep in >35 mph winds without ground tackle. Helical screws essential.

3.3 "Keel Mode" (Beam Reach / Close Reach)

Legs as Foils: 3 x NACA 0035, Span=10.75ft (submerged), Chord=8.5ft. Aspect Ratio (AR) = b²/A = 10.75² / (10.75*8.5) = 1.26. Low AR.

Lift Curve Slope (Cl_alpha) ~ 2*pi*AR/(AR+2) = 2*pi*1.26/3.26 = 2.4 / rad.

Side Force from Wind (30 mph) = 630 lbs. Required Lift = 630 lbs.

Lift = 0.5 * rho_water * V_boat² * Cl * Area_legs.

Area_legs = 3 * 10.75 * 8.5 = 274 ft².

At 4 kts (2 m/s): Dynamic Pressure = 0.5*1025*4 = 2,050 Pa. Lift coeff needed Cl = 630*4.45 / (2050 * 274*0.0929) = 2,800 / 51,700 = 0.054. Alpha = 0.054 / 2.4 = 0.022 rad = 1.3 deg.

Conclusion: At 4+ kts, legs generate massive side force with minimal leeway (< 2°). This design can hold position/ground track in 30-40 mph winds while making 3-4 kts across wind. It effectively "sails" on its foils. Control limit: Leg stall angle ~12-15°. Max side force ~ 630 * (15/1.3) ≈ 7,000 lbs (equiv to ~80 mph wind at 4 kts). Controllable in hurricane force winds IF moving at 4+ kts.

3.4 Running Before Storm (Downwind)

Differential Thrust Yaw Control. Yaw Moment of Inertia (I_zz) ~ Mass * (Gyration Radius)². Mass = 12,500 kg. Beam = 38 ft (11.6m). k_zz ~ 0.4 * Beam = 4.6m. I_zz ~ 2.6e5 kgm².

Thruster Arm = 19 ft (5.8m). 2 Thrusters per leg (1 port/1 stbd? No, 6 total, 2 per leg). Max Thrust per RIM 1.5ft ~ 300-400 lbs (1.5-1.8 kN) @ 10-15 kW each.

Max Yaw Moment = 4 * 1.8kN * 5.8m (using 4 thrusters on one side) = 41,760 Nm.

Angular Accel = 0.16 rad/s². Fast yaw response.

Wind Yaw Moment (Beam wind 50 mph on 326 ft², CP forward of CG): ~5,000 Nm.

Verdict: Thrusters have authority to steer downwind in 50+ mph winds. Danger is broaching (surfing down wave face). Low WPA helps avoid "tripping". Reasonable control likely up to 50-60 mph running off. Sea anchors (series drogue) recommended for survival >50 mph.

4. Seakeeping & Motion Analysis

4.1 Natural Periods & Damping

Mode	Natural Period (Tn)	Critical Damping %	Est. Actual Damping %	Notes
Heave	~4.5 sec	100%	15-20%	Low WPA (65 ft²), High Mass. Heave plates add damping.
Roll	~2.8 sec	100%	8-12%	High GM (Stiff), Heave plates on legs (3x 20ft² @ 21ft arm) provide significant roll damping.
Pitch	~3.5 sec	100%	5-8%	Waterplane symmetric. Heave plates damp pitch less effectively (closer to CG longitudinally).

Heave Plates: 3 legs x 20 ft² = 60 ft² total. Located 10.75 ft below WL. Roll Damping Moment ~ 0.5 * rho * Cd * A_plate * v_roll² * Arm. Cd ~ 1.5. Significant viscous damping.

4.2 Motion Response in Waves (RAO Estimates)

Assumptions: Head Seas (Pitch/Heave), Beam Seas (Roll/Heave). Spectral Peak Period Tp = Wave Period. Resonance check: Wave T (3,5,7s) vs Tn (2.8, 3.5, 4.5s). 5s waves near Pitch resonance. 3s waves near Roll resonance.

Head Seas (Bow into waves)

Wave (Ht/Period)	Pitch Angle (deg)	Vert Accel @ Center (G)	Deck Height Diff Bow-Stern (ft)	Heave (ft)
3ft / 3s	1.5°	0.03 G	1.1 ft	0.8 ft
5ft / 5s (Near Resonance)	3.5°	0.08 G	2.7 ft	2.5 ft
7ft / 7s	2.0°	0.05 G	1.5 ft	3.0 ft

Beam Seas (Waves on side)

Wave (Ht/Period)	Roll Angle (deg)	Vert Accel @ Center (G)	Deck Height Diff Port-Stbd (ft)	Heave (ft)
3ft / 3s (Near Resonance)	4.0°	0.06 G	2.6 ft	1.0 ft
5ft / 5s	2.5°	0.04 G	1.6 ft	2.0 ft
7ft / 7s	1.8°	0.03 G	1.2 ft	2.8 ft

Note: "Deck Height Diff" is vertical motion difference between triangle vertices (22ft from center). Center of triangle (living area) motion is Heave + small rotational component. Vertical Accels < 0.1G are "Comfortable" (ISO 2631). This design is extremely comfortable in 7ft seas.

4.3 Comparison: 100ft Catamaran

Inside Area: This Seastead: ~836 ft² (Triangle) + Loft/Walkway. 100ft Cat: ~2,500-3,000 ft². Cat is 3x larger.
Cost: This Seastead (Est $350k-$450k build). 100ft Cat (Sunreef/Lagoon): $5M - $10M+. Cat is 15-25x cost.
Motions: 100ft Cat has WPA ~ 1,500 ft², Mass ~ 150,000 lbs. Tn_roll ~ 8-10s. In 7ft/7s waves, Cat is near resonance -> Large roll angles (5-10°), high accels. This Seastead Tn_roll=2.8s -> Well above 7s wave freq -> **Motions are 3-5x smaller than 100ft Cat in 7s waves.**
Verdict: YES, this seastead will pitch and roll significantly LESS than a 100ft catamaran in 7ft/7s waves. It behaves like a small SWATH/Semi-sub.

5. Speed, Range & Propulsion

5.1 Resistance & Thrust

6x RIM Drive 1.5ft (450mm). Typical 450mm RIM: 10-15 kW input, 250-400 lbs thrust (1.1-1.8 kN). Assume 12 kW / 300 lbs each. Total 72 kW / 1,800 lbs thrust.

Drag: Legs (3 x NACA 0035, 50% submerged) + House Windage + Appendages.

Hydro Drag ~ 0.5 * rho * V² * Cd * Wetted Area. Wetted ~ 3 * (21.5 * 8.5 * 2.5?) ~ 1,300 ft². Cd ~ 0.004 (foil) + Interference.

Speed	Drag (lbs)	Req Power (kW)	Motor Load
3 mph (2.6 kts)	350	4.5	6%
4 mph (3.5 kts)	620	11	15%
5 mph (4.3 kts)	970	22	30%
6 mph (5.2 kts)	1,400	38	53%
7 mph (6.1 kts)	1,900	60	83%

Hull Speed Equivalent: Leg Length 21.5ft -> ~6.5 kts. Foils delay wave drag rise. Cruise 4-5 kts efficient. 6+ kts high power.

5.2 24/7 Solar Cruising Speed

Avg Solar Power for Propulsion = 2,200 W (from Sec 2.3).

At 2.2 kW shaft -> ~3.0 mph (2.6 kts) continuous, 24/7, zero battery drain.

Solar-Only Sustainable Speed: ~3.0 MPH (2.6 Kts)

5.3 Range Scenarios (240 kWh Bank, 192 kWh Usable)

Scenario	Speed	Power Draw	Range (Nm)	Duration
Battery Only (Calm, Cloudy)	3 mph	4.5 kW	128 Nm	42 hrs
Battery Only	4 mph	11 kW	69 Nm	17 hrs
Battery Only	5 mph	22 kW	43 Nm	8.7 hrs
Typical Caribbean Day (Solar + Batt)	3 mph	Net +2 kW (Charge)	Unlimited	Indefinite
Typical Caribbean Day	4 mph	Net -9 kW (11-2.2)	~240 Nm	~60 hrs
Typical Caribbean Day	5 mph	Net -20 kW	~100 Nm	~20 hrs
20 mph Headwind (+3.8 kW)	3 mph	8.3 kW	70 Nm (Batt only)	23 hrs
20 mph Headwind (+ Solar)	3 mph	Net -6 kW	~180 Nm	~60 hrs

6. Weight & Cost Estimate (Bill of Materials)

Estimates for Marine Aluminum (5083-H116/6061-T6) welded construction. China fabrication (material + labor), shipped to assembly yard. "First Unit" includes NRE/Tooling amortization. "Unit @ 20" assumes production efficiency.

#	Item	Weight (lbs)	Cost (1st Unit)	Cost (Unit @ 20)	Notes
1	Legs (3x NACA 0035, 21.5ft, Al, watertight bulkheads, heave plate mounts, ladder rungs)	9,500	$65,000	$45,000	Complex foil molding/machining or welded plate. Bulkheads every 3ft.
2	Triangle Frame/Wall Structure (Al extrusion/panel, 44ft sides, 7ft high, doors, windows prep)	6,500	$55,000	$38,000	Modular panels (3 sections). Insulation sandwich panels.
3	Floor/Ceiling/Beams (22ft triangle grid + infill panels, grating walkway)	4,000	$30,000	$20,000	Aluminum grating walkway ~$80/ft².
4	6x RIM Drive Thrusters (450mm, 12kW each, controllers)	600	$54,000	$36,000	$9k/unit volume. High efficiency.
5	Solar Panels (18.6 kWp, Marine Flex/Glass, Mounting)	1,200	$28,000	$18,000	$1.50/W installed marine.
6	Solar Charge Controllers (3x MPPT 150V/100A, Redundant)	30	$3,000	$2,000	Victron/Outback class.
7	Batteries (240 kWh LiFePO4, 3x 80kWh modules, BMS, Fire Suppression)	6,875	$31,200	$24,000	Cell cost $90/kWh + Pack $40/kWh.
8	Inverters (3x 12kW/48V Hybrid Inv/Chg, e.g. Victron Quattro)	200	$18,000	$12,000	Triple redundancy. 36kW peak total.
9	Water Makers (2x 60 GPD, ~400W each) + Storage (200 Gal)	600	$12,000	$8,000	Spectra / Rainman. Tanks Al/Plastic.
10	Air Conditioning (3x 12k BTU Mini-split, 1 Condenser)	350	$9,000	$6,000	Marine rated.
11	Insulation (Closed Cell Spray Foam / Aerogel blankets, R-20+)	800	$10,000	$7,000	Critical for condensing/solar gain.
12	Interior Fit-out (Floor, Cabinets, Galley, Head, Furniture, Lightweight)	2,500	$40,000	$28,000	Marine ply/Composite. "MVP" finish.
13	Waste Tanks (Black/Gray, 100 Gal each, Al)	200	$4,000	$2,500
14	Glass/Doors (3x Large Sliding Glass Doors, 6x Portlights, Tempered/Laminated)	800	$25,000	$16,000	Custom curve/triangle. Big cost driver.
15	Refrigeration (Fridge/Freezer 12V, High Eff)	150	$3,500	$2,500	Vitrifrigo/Isotherm.
16	Davit/Crane for Dinghy (Al, 500lb cap, Electric Winch)	300	$8,000	$5,000	Mounted on aft triangle vertex.
17	Safety Eq (Life Raft 4-man, EPIRB, PFDs, Flares, Fire Sys, Bilge)	200	$8,000	$5,500
18	Dinghy (14ft RIB Hypalon, Deflated) + Yamaha HARMO Electric	400	$18,000	$14,000	RIB $8k, Motor $10k.
19	Sea Anchors (2x Para-Tech 18ft / Series Drogue)	100	$3,000	$2,000
20	Kite Propulsion (Stack 20x 6ft Foil Kites, Lines, Reel, Auto-pilot interface)	150	$15,000	$10,000	Custom stack system. High reward/High complexity.
21	Leg Air Bags (8 per leg x 3 = 24 bags, Inflation system)	150	$6,000	$4,000	CO2/Nitrogen trigger.
22	Starlink (2x Maritime Flat High Perf, Mounts, PoE)	50	$5,000	$5,000	Hardware $2.5k ea. Service separate.
23	Trash Compactor (Marine, 12V)	80	$2,500	$1,800
24	Heave Plates (3x 20 ft², Al, Bolt-on)	450	$4,500	$3,000	Perforated for tuning.
25	Incinerating Toilet (Cinderella / Incinolet)	100	$4,500	$3,500	High power draw managed by inverter.
26	Helical Mooring System (3x Units: 2 screws + Motor + Tensioner)	600	$15,000	$10,000	Hydraulic/Electric drive.
27	Electrical Distribution (Busbars, Breakers, Wiring, Monitoring, N2 Gen)	500	$20,000	$14,000	ABYC/ISO Standards. 3-zone redundancy.
28	Navigation/Control (Autopilot, Radar, AIS, Cameras, Computer, Sensors)	100	$12,000	$8,000	Redundant CAN bus.
29	Assembly Yard Labor (2 weeks, 4 people, Travel, Crane, Consumables)	-	$25,000	$15,000	Excludes shipping container freight.
30	Engineering/Classification (Design Review, Flag Survey Prep)	-	$30,000	$5,000	One-time NRE heavy on Unit 1.
TOTALS		~37,885 lbs	$564,200	$370,800

Weight Check: Structure/Outfit ~31,000 lbs + Batteries 6,875 lbs = 37,875 lbs. Target Displacement 27,500 lbs. CRITICAL OVERRUN: ~10,400 lbs (38%) OVERWEIGHT.

Mandatory Weight Reduction: 1. Reduce Battery to 15% Disp (4,100 lbs / 144 kWh). 2. Thin Leg Foil Shells (Advanced FEA). 3. Composite (Carbon/Glass) Legs & House Panels ($$). 4. Reduce Interior Fitout. 5. Accept 35,000 lbs Displacement (Deeper Draft / Larger Foils). Analysis below assumes weight savings achieved to hit 27,500 lbs target.

7. Registration & Flag State (Panama / Liberia)

Classification: "Trimaran Yacht" vs "Platform"

IMO/Loadline: < 24m (78.7 ft) LOA? Triangle side = 44ft. Legs = 21.5ft. LOA ~ 44ft + leg overhang? ~50ft. < 24m. Exempt from SOLAS/Loadline Convention.
Flag State (Panama/Liberia): Both allow "Pleasure Yacht" registration for private use < 24m, < 12 pax.
Challenge: "Seastead" implies stationary living. Flags hate "Artificial Islands". You must prove **seaworthiness and mobility**.
Requirements:
1. Classification Society Survey (RINA, Bureau Veritas, ABS) for "Yacht" notation.
2. Stability Booklet (Intact & Damage).
3. Propulsion capable of 4+ kts (You have 6+ kts).
4. Steering & Nav Lights (Colregs).
5. Helical Anchors = "Ground Tackle", not permanent attachment.
Verdict: Registerable as "Motor Trimaran Yacht" in Panama/Liberia. Cost ~$2k-$5k/yr + Survey ($5k-$10k initial). Key: Keep it classified as a vessel that *moves*, not a platform that *stays*.

8. Viability Feedback & Risk Assessment

8.1 Profitability as a Product

Market Niche: "Liveaboard Adventurers" + "Digital Nomads" + "Preppers/Resilience". Addressable market: ~5,000-10,000 serious buyers globally? Niche but loyal.
Price Point: $370k (Unit 20 cost) + $100k Margin/Overhead = **$470k Retail**. Competitive vs 40ft Cat ($600k+) for *space/stability*, but lacks speed/range/brand.
Business Model: Sell "Kit + Assembly Supervision" not finished boat. Reduces liability/yard overhead. Target 10 units/yr = $4.7M Rev. Viable small business.

8.2 Design Improvements (Critical)

WEIGHT CRISIS: Current estimate 38k lbs vs 27.5k target. Switch Legs & House to Sandwich Composite (Foam/Carbon/Epoxy). Saves 40% weight (15,000 lbs). Cost +$50k/unit. Essential.
Container Packing: 3 Legs stacked on right (3 x 35.7" = 89.1" > 89" container height). Does not fit. Must reduce foil thickness (NACA 0030 -> 2.55" thick, 3x=76.5") OR ship legs diagonal/on rack. Reduce chord to 8.0ft?
Leg Attachments: "Near points of triangle" creates huge bending moment on leg root. Needs massive internal flange/bulkhead. Design for "Snap Shackle" quick connect for containerization?
Walkway Height: "1 ft higher than bottom of wall". Wall sits on legs? If leg top = triangle bottom, walkway is 1ft above water? No, legs stick up 10ft above water. Walkway at 11ft? Clarify geometry.
RIM Drives: 1.5ft diameter is small for 27,500 lbs displacement. 6x 18" props = 1.4 m² disc area. Disc Loading = 12,500kg / 1.4 = 8,900 kg/m². High. Expect cavitation/ventilation in waves. Go to 24" (600mm) or 8x 18".
Kites: 20 kites stacked = Tangles. Start with 1-2 large (15-20m²) foil kites. Auto-launch/retrieve is unsolved hard problem.

8.3 Single Points of Failure (SPOF)

System	Risk	Mitigation
Leg Hull Integrity	Collision/Grounding -> Flooding -> Capsize	8 Watertight Bulkheads/leg + 8 Airbags (Good). Add Collision Bulkhead at front.
Thruster Failure	Loss of Station Keeping / Steering	6 Thrusters (Redundant). Differential steer on 4. Add 1 Bow Thruster for harbor.
Battery Fire	Total Loss	LFP Chemistry (Good). 3 Isolated Modules (Good). Add Aerosol Suppression per module.
Structural Connection (Leg-House)	Fatigue Fracture	FEM Analysis critical. Inspectable pinned joints.
Water Maker	Dehydration	2 Units (Good). Manual Backpack Katadyn backup.
Starlink	Comms/Nav Loss	2 Units (Good). Iridium GO! Backup ($500).

8.4 Hurricane Season Strategy (Caribbean South Edge)

Speed: 5-6 kts sustained (Solar+Batt) / 7+ kts (Batt only). 24hr Range ~ 120-140 Nm.

Forecast (2028): 5-day track error ~ 150-200 Nm. Intensity error ~ 1 Cat.

Verdict: MARGINAL. You can outrun the *average* error cone if you leave at 72hrs. You **cannot** outrun a rapid intensification (RI) event forming on top of you (e.g. Otel, Michael). Requirement: Hardened "Storm Mode" (Helical Anchors + Sea Anchors + Submerged Survival) must work. Do not rely solely on running.

8.5 Market Niche Size

"The Floating Cabin" Market: People wanting Stability > Speed, Space > Style, Autonomy > Marina Life.

Estimated Global Demand: **50-100 units/year** at $450k-$550k if certified (CE Cat A / RINA Pleasure Yacht). First 20 units are "Early Adopters" tolerating bugs. Path to 100/yr requires classification and dealer network.

9. Executive Summary

Total Cost (1st Unit): ~$565,000

Target Cost (Series 20): ~$370,000

Retail Target (Series 20): ~$475,000

Metric	Value
Average Solar Production	~98 kWh/day (4.1 kW continuous)
Average Hotel Load (No Prop)	~41 kWh/day (1.7 kW continuous)
Avg Power for Propulsion (24/7)	~57 kWh/day (2.4 kW continuous)
Solar-Only Sustainable Speed	3.0 MPH (2.6 Kts)
Battery Bank (Target)	144 kWh (4,100 lbs) - Reduced from 240kWh to meet weight
Extra Buoyancy (Payload)	~2,500 - 4,000 lbs (After structure, batteries, systems. Target Disp 27,500 - Lightship ~23,500)
24/7 Average Speed (Caribbean)	3.0 - 3.5 MPH (Solar + Battery Buffer)
Max Speed (Calm)	6.5 - 7.0 Kts (7.5 - 8 MPH)
Motions in 7ft/7s Waves (Beam)	Roll < 2°, Vert Accel < 0.04g (Excellent)
Registration	Feasible as "Trimaran Yacht" (<24m) in Panama/Liberia

Final Go/No-Go

CONCEPT VIABLE but requires **Immediate Engineering Iteration** on: 1. **Weight Reduction** (Composite Legs/House mandatory). 2. **Container Fit** (Leg thickness/Chord adjustment). 3. **Thruster Sizing** (Increase to 24" or add count). 4. **Storm Survival Protocol** (Hardened Anchoring/Submergence).

The "SWATH-lite" foil leg geometry provides genuine seakeeping superiority over catamarans/monohulls in the 20-50ft range. The energy autonomy is achievable. The containerizable kit-logistics is a strong commercial differentiator.