Height of triangle (centerline): 40 × sin(60°) = 34.64 ft
Centroid is 34.64 / 3 = 11.55 ft from the back edge
Living Area Placement
The living area is 12 ft wide and needs to fit inside the triangular frame. At the front vertex, the triangle narrows to a point. The furthest forward you can place a 12-ft-wide rectangle is where the triangle is 12 ft wide.
Triangle width at distance d from front vertex: W(d) = d × (40 / 34.64) = d × 1.1547
Solve W(d) = 12 → d = 12 / 1.1547 = 10.39 ft from front vertex
Front edge of living area: 10.39 ft from front vertex
Back edge of living area: at the back edge, 34.64 ft from front vertex
Living area length: 34.64 − 10.39 = 24.25 ft
Living area dimensions: 12 ft wide × 24.25 ft long × 8 ft tall
Living area floor area: ~291 sq ft
Legs/Wings (NACA Foil Struts)
3 legs, each 19 ft long (vertical span), 10 ft chord, 2 ft max thickness
NACA foil cross-section (approx NACA 0020 scaled: 20% thickness ratio at 2 ft / 10 ft chord)
Each leg: 50% submerged = 9.5 ft underwater, 9.5 ft above water
All oriented with leading edge forward (parallel alignment)
40 ft
Triangle Side Length
291 ft²
Living Area Floor
3 × 19 ft
Leg Height (each)
9.5 ft
Draft (submerged leg)
☀️ 2. Solar Panel Area & Installed Wattage
Roof of Living Area
12 ft × 24.25 ft = 291 sq ft
Fold-Down Side Panels
The living area is 8 ft tall. Fold-down panels on both left and right sides extend 8 ft outward, folding up level with the roof when deployed.
Left panel: 8 ft × 24.25 ft = 194 sq ft
Right panel: 8 ft × 24.25 ft = 194 sq ft
Total side panels: 388 sq ft
Total Solar Area
Total solar area: 291 + 388 = ~679 sq ft ≈ 63.1 m²
Installed Wattage
Modern marine-grade rigid solar panels produce approximately 190–210 W/m² (about 19–20 W/ft²). Using a practical figure of 200 W/m² (accounting for panel spacing, mounting hardware, and real-world panel sizes):
63.1 m² × 200 W/m² = ~12,600 watts (12.6 kW)
With a conservative packing factor of 85% (gaps, wiring runs, mounting frames):
Practical installed capacity: ~10,700 W (10.7 kW)
In the Caribbean (avg ~5.5 peak sun hours/day): ~58.9 kWh/day average production
679 ft²
Total Solar Area
10.7 kW
Installed Solar Capacity
58.9 kWh
Daily Energy (Caribbean)
⚖️ 3. Structural Weight Estimate
Triangle Frame
3 sides × 40 ft each = 120 linear feet of aluminum box beam. Using 6" × 6" × ¼" aluminum box beam (~4.36 lb/ft):
120 ft × 4.36 lb/ft ≈ 523 lbs
Add cross bracing, gussets, and attachment points (~40% additional):
523 × 1.4 ≈ 730 lbs
Legs / Wings (3 total)
Each leg: NACA foil, 19 ft span, 10 ft chord, 2 ft max thickness. Built as a semi-monocoque structure with aluminum skin, ribs, and spars.
Skin area per leg (both sides + leading/trailing edge): approx 2 × 19 × 10 + edge ≈ 400 sq ft
Using 3/16" (4.76mm) 5086 aluminum plate for skin: ~2.75 lb/ft²
6 × RIM drive thrusters (est. 35 lbs each installed)
210
Solar panels (10.7 kW ÷ 400W panels × ~50 lbs)
~1,340
Ladders (3, built into legs)
90
Davit/crane for RIB
250
Wiring, plumbing, misc hardware
400
Fasteners, welding rod, sealant
200
Additional items: ~2,490 lbs
Total Structural Weight
Component
Weight (lbs)
Triangle frame
730
3 Legs/Wings
4,680
Living area structure
3,890
Railing & netting
450
Additional items
2,490
TOTAL STRUCTURE
~12,240 lbs
Estimated bare structural weight: ~12,200 lbs (5,535 kg) This includes the aluminum structure, solar panels, thrusters, davit, and basic hardware but NOT furnishings, batteries, water, provisions, stabilizers, or the RIB boat.
🌊 4. Buoyancy Analysis
Cross-Sectional Area of One Leg
A NACA 0020 foil with 10 ft chord and 2 ft max thickness has a cross-sectional area approximately 68% of the bounding rectangle (standard for NACA 00xx foils):
Cross-section area = 0.68 × 10 ft × 2 ft = 13.6 sq ft per leg
Submerged Volume per Leg
Volume = 13.6 ft² × 9.5 ft (submerged span) = 129.2 cu ft per leg
Total Submerged Volume (3 Legs)
Total = 3 × 129.2 = 387.6 cu ft
Total Buoyancy Force
Seawater weighs ~64 lbs/cu ft:
387.6 ft³ × 64 lb/ft³ = 24,806 lbs of buoyancy
Available Payload After Structure
24,806 − 12,240 = 12,566 lbs available for payload
Remaining buoyancy for payload: ~12,500 lbs (5,670 kg)
Typical Payload Budget
Item
Weight (lbs)
LiFePO4 batteries (4,000 lbs as specified)
4,000
14 ft RIB boat + outboard
650
Fresh water (100 gallons)
835
Furnishings, appliances, galley
1,500
Provisions, personal gear
500
3 Active stabilizer assemblies
360
Watermaker, electronics, inverters
400
People (4 × 180 lbs)
720
Total Payload
8,965
Remaining Reserve Buoyancy
~3,535 lbs
With all payload loaded, ~3,500 lbs reserve buoyancy remains. This means the legs would be submerged slightly less than 9.5 ft — about 8.1 ft submerged under full load, giving comfortable freeboard margin. At maximum load the waterline stays well below the top of the legs, with about 10.9 ft of leg above water.
Buoyancy Force Per Additional Foot of Submersion
One leg: 13.6 ft² × 1 ft × 64 lb/ft³ = 870 lbs per foot per leg
Three legs: 3 × 870 = 2,611 lbs per foot (all 3 legs)
Each additional foot of water level around one leg produces ~870 lbs of buoyancy change.
Across all 3 legs: ~2,611 lbs per foot.
✈️ 5. Active Stabilizer Design
Concept
Each stabilizer is a small "airplane" that wraps around the trailing edge of the main leg, submerged. It has a main wing and a tail with an actuator. By adjusting the tail angle, the angle of attack of the main wing changes, creating up or down hydrodynamic forces to counteract wave-induced heave.
The pivot point is at approximately the quarter-chord of the stabilizer wing, where the center of lift acts, so only a small actuator on the tail is needed to change the effective angle of attack.
Force Required to Counter 1 Foot of Wave
From the buoyancy analysis, one foot of wave displacement across all 3 legs involves:
Force needed per leg: ~870 lbs = 3,870 N
However, the SWATH hull passively attenuates waves significantly. In a 4-ft wave, the actual heave at the platform might be only 1.5–2 ft already (passive attenuation of ~50–60%). So the stabilizer only needs to counter the residual motion, which might be 870 lbs per foot of residual heave per leg.
Sizing the Stabilizer Wing
Using hydrodynamic lift equation at 5 knots (2.57 m/s):
L = ½ × ρ × V² × A × C_L
ρ (seawater) = 1025 kg/m³
V = 2.57 m/s (5 knots)
C_L = 0.8 (achievable with active angle of attack control, moderate angles)
Target force per stabilizer: 870 lbs = 3,870 N
A = 3,870 / (0.5 × 1025 × 2.57² × 0.8)
A = 3,870 / (0.5 × 1025 × 6.6 × 0.8)
A = 3,870 / 2,706
A = 1.43 m² ≈ 15.4 sq ft
Stabilizer Dimensions
Target: ~15.4 sq ft of main wing area per stabilizer. A practical layout:
Main wing: 5 ft span × 3.1 ft chord = 15.5 sq ft (NACA 0012 or similar)
Tail surface: ~25% of main wing = ~3.9 sq ft (2.5 ft span × 1.6 ft chord)
Connecting fuselage/fairing: ~2.5 ft long, streamlined around the leg trailing edge
Total assembly length (nose to tail): ~6 ft
Total wingspan: 5 ft (extends 2.5 ft each side of the leg)
Stabilizer Location
Mounted ~3–5 ft below the waterline on each leg, where it remains submerged through wave troughs. The attachment wraps around the thin trailing edge of the main NACA leg foil, with the pivot at the quarter-chord point of the stabilizer wing.
Wave Reduction Analysis
If a stabilizer can reduce 1 foot from a wave peak (pushing down) and 1 foot from a wave trough (pushing up), the total felt wave height is reduced by 2 feet.
So a 4-foot wave → felt as ~2-foot wave? Yes, conceptually correct.
However, the SWATH geometry already passively attenuates significantly, so the combined effect is even better. See the detailed wave response table in Section 8.
Stabilizer Speed Dependence
Lift is proportional to V². The stabilizer sized for 870 lbs at 5 knots produces:
Speed
Force per stabilizer
Wave feet countered per leg
4 knots
557 lbs
0.64 ft
5 knots
870 lbs
1.00 ft
6 knots
1,253 lbs
1.44 ft
At Anchor (0 knots)
At zero speed, hydrodynamic stabilizers produce no force. However, even waves passing the seastead at anchor create relative water flow. A 4-ft wave with 6-second period produces orbital velocities of ~3–4 ft/s (~2–2.4 knots), giving roughly 30–40% of the 5-knot force. So even at anchor, the stabilizers provide some benefit: ~250–350 lbs per stabilizer, countering roughly 0.3–0.4 ft of wave per leg. Combined with passive SWATH attenuation, this still helps noticeably.
Stabilizer Weight & Cost
Component
Weight (lbs)
Cost (batch of 20, China)
Main wing (5086 Al, welded, internal ribs)
55
$800
Tail surface + hinge
12
$250
Fuselage/fairing & leg attachment clamp
20
$400
Linear actuator (marine, 12/24V, ~200 lb-force)
8
$150
Position sensor, wiring, controller board
3
$200
Fasteners, zincs, sealant
4
$50
Total per stabilizer
~102 lbs
~$1,850
Set of 3 stabilizers
~306 lbs
~$5,550
One-off pricing: For a single set of 3, expect approximately $3,200 per stabilizer (~$9,600 for a set) due to fixture/tooling amortization.
Actuator Power Consumption
Each tail actuator: ~50W average (small servo actuator, intermittent duty). Controller/sensor: ~5W.
3 stabilizers × 55W = ~165W total for active stabilization system
🚀 6. Propulsion & Speed Analysis
Resistance Estimation
This SWATH design has very low drag due to:
Small waterplane area (only 3 thin foil-shaped struts pierce the surface)
No large hull creating wave-making resistance
NACA foil shapes minimize form drag
Above-water structure creates only aerodynamic drag
Hydrodynamic Drag (Submerged Legs)
Each leg submerged portion: 10 ft chord × 9.5 ft span = 95 sq ft wetted area per side × 2 sides = 190 sq ft per leg. Three legs = 570 sq ft total wetted area.
Friction drag: C_f ≈ 0.003 (turbulent, Reynolds number ~3×10⁶ at 5 kts)
D_friction = ½ × ρ × V² × S_wetted × C_f
Form drag coefficient for NACA 0020 at 0° AoA: C_d ≈ 0.008–0.012 (referenced to chord×span)
Frontal area per leg: 2 ft × 9.5 ft = 19 sq ft → total 57 sq ft
Using C_d = 0.010 on plan area (10 × 9.5 = 95 sq ft per leg, 285 sq ft total)
Wave-Making Drag
At these low speeds (Froude number ~0.08 based on waterline "length" of the strut chord), wave-making resistance is minimal. However, the 3 surface-piercing struts each create a small wave system. Estimated at ~20% of friction+form drag.
Aerodynamic Drag
Living area frontal area: 12 ft × 8 ft = 96 sq ft. Triangle frame frontal contribution: ~20 sq ft. Upper leg portions: ~15 sq ft. Total ~131 sq ft.
At 5 knots (8.4 ft/s) in air (ρ = 0.0023 slugs/ft³), aero drag is minimal (~5–10 lbs). We'll include it but it's small.
Stabilizer Drag
3 stabilizer assemblies, each ~15.5 sq ft wing + 3.9 sq ft tail + fairing. Estimated drag coefficient ~0.015 on total area. At neutral (0° AoA) they add minimal drag. When actively deflecting, parasitic drag increases.
Total Resistance & Power Required
Speed
Hydro Drag (lbs)
Aero Drag (lbs)
Stabilizer Drag (lbs)
Total Drag (lbs)
Power at Prop (W)
Electrical Power (W)*
4 kts (2.06 m/s)
85
3
7
95
590
985
5 kts (2.57 m/s)
132
5
11
148
1,150
1,920
6 kts (3.09 m/s)
192
7
16
215
2,000
3,335
*Electrical power assumes 60% overall efficiency (RIM drive thruster efficiency ~70% × controller/wiring ~85%). Power = Force × Velocity / efficiency.
Power Without Stabilizers
Speed
Total Drag (lbs)
Electrical Power (W)
4 kts
88
910
5 kts
137
1,770
6 kts
199
3,090
Stabilizers add roughly 8–10% drag when at neutral. When actively working against waves, instantaneous drag can spike higher, but average additional power for stabilization actuation is only ~165W. Total additional power cost of stabilizers (drag + actuation): approximately 240–410W depending on speed and sea state.
🔋 7. Battery Range & Endurance
Battery Capacity
4,000 lbs of LiFePO4 batteries. LiFePO4 energy density: ~50 Wh/lb at cell level, ~42 Wh/lb at pack level (with BMS, casing, wiring).
4,000 lbs × 42 Wh/lb = 168,000 Wh = 168 kWh
Usable capacity (90% DoD for LiFePO4 longevity):
151.2 kWh usable
Endurance Calculations (Propulsion + 1,000W House Load)
Speed
Propulsion (W)
Stabilizers (W)
House (W)
Total (W)
Hours
Range (nm)
Without Stabilizers
4 kts
910
0
1,000
1,910
79.2
317
5 kts
1,770
0
1,000
2,770
54.6
273
6 kts
3,090
0
1,000
4,090
37.0
222
With Stabilizers Active
4 kts
985
165
1,000
2,150
70.3
281
5 kts
1,920
165
1,000
3,085
49.0
245
6 kts
3,335
165
1,000
4,500
33.6
202
Days to Charge Batteries from Solar (Caribbean)
Solar production: ~58.9 kWh/day
Minus house loads (24h × 1000W): 24 kWh/day
Available for charging: ~34.9 kWh/day
Battery capacity: 151.2 kWh usable
Days to full charge from empty: 151.2 / 34.9 = ~4.3 days
Caribbean charging time: ~4–5 days from empty to full (accounting for some cloudy periods and MPPT losses). If you continue running house loads only and not moving, you'll have a full battery in under 5 days on average.
🌊 8. Wave Response & Motion Analysis
Passive SWATH Attenuation
The SWATH (Small Waterplane Area Twin/Tri Hull) design inherently reduces wave-induced motion because:
The waterplane area is very small (only 3 struts of 10ft × 2ft max width each = ~30 sq ft of waterplane vs. ~340 sq ft for a comparable monohull)
Wave forcing is proportional to waterplane area
The submerged volume (buoyancy) is well below the surface where wave orbital velocities decay exponentially
The wide triangle stance (40 ft) provides excellent roll stability
For typical ocean waves (6–8 second period), a SWATH with waterplane area ratio of ~9% (30/340) of an equivalent monohull can achieve passive heave attenuation of 50–70% depending on wave period relative to the vessel's natural period.
Natural heave period: T_n = 2π × √(m / (ρ × g × A_wp))
m = ~21,200 lbs / 32.2 = 658 slugs total mass
A_wp ≈ 3 × (10 ft × 0.4 ft avg width at waterline for NACA shape) = 12 sq ft
(Note: the NACA 0020 is only ~0.4 ft wide right at the waterline due to the foil taper)
The natural period of ~5.8 seconds is close to typical Caribbean wind-wave periods (5–8 sec). This means we need to be careful about resonance. Ideally, we'd want the natural period well above the wave period (for a SWATH, typically tuned to 8–12 seconds by adjusting geometry). The active stabilizers become even more valuable here to provide damping near resonance.
Combined Passive + Active Motion Estimates
The following table estimates the felt heave (vertical motion) at the platform for different wave heights and speeds. The passive SWATH attenuation varies with wave period. We assume typical Caribbean wind waves with periods of 5–7 seconds.
Wave Height (ft)
Speed
Passive Only
Passive + Active Stabilizers
Heave (ft)
Attenuation
Heave (ft)
Total Attenuation
3 ft
4 kts
1.5
50%
0.9
70%
5 kts
1.4
53%
0.6
80%
6 kts
1.3
57%
0.4
87%
4 ft
4 kts
2.0
50%
1.3
68%
5 kts
1.8
55%
0.9
78%
6 kts
1.7
58%
0.5
88%
5 ft
4 kts
2.5
50%
1.8
64%
5 kts
2.3
54%
1.4
72%
6 kts
2.1
58%
0.8
84%
Stabilizer Wave Reduction Breakdown by Speed
Speed
Force per stabilizer (lbs)
Crest reduction per leg (ft)
Trough reduction per leg (ft)
Total felt reduction (ft)
4 kts
557
0.64
0.64
~1.3 ft
5 kts
870
1.00
1.00
~2.0 ft
6 kts
1,253
1.44
1.44
~2.9 ft
The "total felt reduction" represents the maximum wave height that the stabilizers alone could fully counteract. In practice, they work on the residual motion after passive SWATH attenuation, so the effect is multiplicative — they reduce the already-reduced motion further.
Key takeaway: At 5 knots in 4-ft waves, passive SWATH reduces heave to ~1.8 ft. Active stabilizers then reduce this to ~0.9 ft. The platform feels like it's in less than 1-foot seas — remarkably comfortable. At 6 knots in 4-ft seas, felt motion drops to about 0.5 ft.
Pitch and Roll
With a 40-ft triangle base and 3-point support:
Roll stability (beam seas): The 40-ft beam provides exceptional roll resistance. Even without stabilizers, roll in 4-ft beam seas would be ~2–3°. With stabilizers, under 1°.
Pitch stability: Front-to-back distance is 34.6 ft. Similar excellent stability. Pitch in 4-ft head seas: ~3–4° passive, ~1–2° with stabilizers active at 5 kts.
⛵ 9. Solar-Only 24/7 Cruising Speed
Power Budget for Continuous Cruising
Average solar production: 58,900 Wh / 24 hours = 2,454 W average
(Note: this is the average over 24h; actual generation is ~10,700W for ~5.5 hours)
House load: 1,000 W continuous
Available for propulsion: 2,454 − 1,000 = 1,454 W
The batteries serve as a buffer — charging during daytime, discharging at night. With 151 kWh of usable storage, this easily covers overnight propulsion.
Without Stabilizers
1,454W available for propulsion
At 4 kts: needs 910W → YES — can sustain 4 knots 24/7 with 544W surplus
At 5 kts: needs 1,770W → NO — 316W deficit
Interpolating for exact sustainable speed (without stabilizers):
Power ≈ k × V³ (approximately, for this speed range)
At 4 kts: 910W → k = 910/64 = 14.22
At 5 kts: 1770W → k = 1770/125 = 14.16
Average k ≈ 14.19
1,454 = 14.19 × V³ → V³ = 102.5 → V = 4.68 knots
Sustainable 24/7 solar-only speed (no stabilizers): ~4.7 knots
Daily distance: 4.7 × 24 = ~113 nautical miles per day
With Stabilizers Active
Stabilizer power: 165W (actuation) + ~75W additional drag avg = ~240W
Available for propulsion: 1,454 − 240 = 1,214W
1,214 = 14.19 × V³ → V³ = 85.6 → V = 4.41 knots
Sustainable 24/7 solar-only speed (with stabilizers): ~4.4 knots
Daily distance: 4.4 × 24 = ~106 nautical miles per day
Ocean Crossing Estimates
Route
Distance (nm)
Days (no stab.)
Days (with stab.)
Canary Islands → Caribbean (trade wind route)
2,700
24
25
Panama → Marquesas (Pacific)
3,900
35
37
Caribbean island hopping (e.g., BVI to Grenada)
450
4
4.2
Note: These assume consistent Caribbean-level solar. Higher latitudes or persistent cloud cover would reduce speed. Conversely, favorable currents (Gulf Stream, trade wind currents at 0.5–1 kt) could add 12–24 nm/day.
💰 10. Cost Estimates
Single Unit — Built in China
Component
Cost (USD)
Notes
Marine aluminum structure (frame, legs, living area)
$85,000
~12,200 lbs × $7/lb avg (material + fabrication)
Marine windows & doors
$8,000
Tempered glass, marine-grade frames
Solar panels (10.7 kW)
$6,500
~$0.60/W marine-grade panels in China
Fold-down panel frames & hinges
$3,500
Included in structure above, additional hardware
Solar charge controllers & inverters
$4,000
MPPT controllers, 3kW inverter
LiFePO4 batteries (168 kWh / ~4,000 lbs)
$25,000
~$150/kWh at pack level from China
6 × RIM drive thrusters
$18,000
~$3,000 each installed
Thruster controllers & wiring
$4,500
ESCs, throttle control, wiring harness
3 × Active stabilizers (complete)
$9,600
One-off pricing
Stabilizer control system (IMU, computer, software)
$3,000
Motion sensing + control algorithm
Davit/crane
$3,500
Manual or electric, 1000 lb capacity
Railing & netting
$4,000
Aluminum rail + Dyneema netting
Navigation electronics
$5,000
Chartplotter, AIS, radar, VHF, compass
Plumbing (water tanks, pump, watermaker)
$6,000
Basic system with small watermaker
Interior fitout (basic galley, head, berths)
$15,000
Functional marine interior
Lighting, fans, switches, electrical panel
$3,500
LED throughout, marine panel
Paint & anti-fouling
$4,000
Below waterline anti-fouling + topside paint
Safety equipment (life raft, extinguishers, etc.)
$5,000
Offshore-rated safety package
Assembly labor (additional to per-lb fab cost)
$12,000
Final assembly, testing, commissioning
Shipping / transport to port
$8,000
Breakbulk or flat-rack container
SINGLE UNIT TOTAL
~$234,000
Not included: 14 ft RIB boat + outboard (~$8,000–15,000 depending on brand), import duties, commissioning voyage, design engineering fees for first unit.
Batch of 20 — Built in China
With a production run of 20 units, significant savings come from:
Aluminum structure: jigs, fixtures, CNC programming amortized over 20 units → ~30% savings
Bulk material purchasing: ~10–15% savings on aluminum, electronics
Stabilizers: batch pricing ($5,550 vs $9,600 per set of 3)
Volume pricing on batteries, solar, thrusters: ~15–20% savings
Reduced per-unit engineering, QC overhead
Shipping: consolidated container loads → ~40% savings per unit
Component
Cost per unit (batch of 20)
Marine aluminum structure
$60,000
Marine windows & doors
$6,000
Solar panels (10.7 kW)
$5,000
Fold-down panel frames
$2,500
Solar charge controllers & inverters
$3,200
LiFePO4 batteries (168 kWh)
$20,000
6 × RIM drive thrusters
$13,500
Thruster controllers & wiring
$3,500
3 × Active stabilizers
$5,550
Stabilizer control system
$2,000
Davit/crane
$2,500
Railing & netting
$3,000
Navigation electronics
$4,000
Plumbing system
$4,500
Interior fitout
$11,000
Lighting, electrical panel
$2,500
Paint & anti-fouling
$3,000
Safety equipment
$4,000
Assembly labor
$8,000
Shipping per unit
$5,000
PER UNIT COST (Batch of 20)
~$168,000
$234,000
Single Unit Cost
$168,000
Per Unit (Batch of 20)
$3.36M
Total Batch of 20
28%
Batch Savings
First article / design engineering: Budget an additional $30,000–50,000 for the first unit to cover detailed engineering drawings, structural analysis (FEA), stability calculations, and prototype validation. This is a one-time cost amortized over the production run.
📊 Summary of Key Figures
679 ft²
Total Solar Area
10.7 kW
Solar Installed
12,240 lbs
Structural Weight
12,500 lbs
Payload Capacity
870 lbs/ft
Buoyancy per Foot per Leg
168 kWh
Battery Capacity
4.7 kts
24/7 Solar Speed
113 nm/day
Daily Solar Range
273 nm
Battery Range @ 5 kts
~80%
Wave Reduction @ 5 kts (4ft seas)
102 lbs
Stabilizer Weight (each)
$168K
Per Unit (Batch of 20)
⚠️ Important Notes & Disclaimers
All figures are engineering estimates based on first-principles calculations and industry benchmarks. Detailed naval architecture analysis (CFD, FEA, tank testing) is required before construction.
The natural heave period (~5.8 sec) being close to common wave periods is a concern that should be addressed in detailed design — possibly by adjusting the waterplane area profile or adding passive damping.
Weight estimates assume competent marine aluminum fabrication (5086/6061-T6) with proper welding. Actual weights could vary ±15%.
Cost estimates are based on 2024 pricing from Chinese marine fabricators. Costs may vary with material prices, exchange rates, and specific supplier capabilities.
The stabilizer effectiveness estimates assume a well-tuned control system with adequate sensor response time. Development of the control algorithm is a non-trivial engineering task.
Propulsion power estimates assume clean hull surfaces. Biofouling can increase drag 20–40% over time.
Ocean crossing should include weather routing and contingency planning. Solar production varies significantly with latitude, season, and weather.
Classification society review (e.g., Lloyd's, DNV, BV) may be required depending on intended use and jurisdiction.