Below is a complete, self‑contained HTML page that summarises the route, the speed model, a segment‑by‑segment breakdown and the resulting travel‑time estimate. You can save this code as an `.html` file (e.g., `seastead_circumnavigation.html`) and open it in any browser or embed it in a site.
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Solar‑Kite Seastead Circumnavigation Estimate
Circumnavigation Estimate for a Solar‑Kite‑Powered Seastead
This page provides a rough engineering estimate of how long it would take a solar‑ and kite‑propelled seastead to circle the globe while staying mostly in “low‑risk” latitudes (avoiding the Roaring Forties & Furious Fifties) and avoiding tropical cyclones.
1. Propuls ion Capabilities
Kite: 3 mph when the true wind is within ±30° of the desired heading (down‑wind).
Solar (day): 2 mph for up to 6 h per day (when the sun is high).
Solar (night): 1 mph for the remaining 18 h.
These three modes do not add – we always use the fastest applicable mode.
Because the kite is the fastest, we will run it whenever the wind direction permits. Typical ocean‑wind statistics suggest we can expect kite‑friendly conditions for roughly 8 – 10 h per day in the trade‑wind belts and 6 – 8 h per day in the mid‑latitude westerlies.
2. Assumed Average Speed (including a modest current‑assist)
Effective average speed ≈ 2.1 mph (≈ 50 mi / day).
In less favorable wind regimes (e.g., the South Atlantic) the kite may be usable only ~5 h/day, which lowers the average to ~1.8 mph; in the best sections (North Atlantic Gulf Stream) it can be ~2.5 mph. The range of 1.8 – 2.5 mph gives a realistic envelope for the estimate.
3. Proposed Low‑Latitude Route (West‑about)
The route stays north of ≈ 35° S except for a short stretch around Cape Agulhas, keeping wave heights generally under 15 ft. The main way‑points are:
Start: Hawaiian Islands (≈ 21° N, 158° W)
Philippines / Indonesia (≈ 10° N, 130° E) – passing through the Indonesian Through‑flow.
Across the Indian Ocean at ~10° S (South Equatorial Current).
Round the southern tip of Africa near Cape Agulhas (≈ 35° S, 20° E).
Cross the South Atlantic to the Caribbean (≈ 15° N, 70° W).
Head north‑east in the Gulf Stream / North Atlantic Current to ~40° N.
Return to the Pacific via the Panama Canal and back to Hawaii.
Figure – Approximate low‑latitude circumnavigation (west‑about). The dashed line is schematic; real routing would follow weather‑forecast adjustments.
4. Segment Breakdown
Segment
Approx. Distance (mi)
Assumed Avg. Speed (mph)
Time (days)
Pacific (Hawaii → Philippines)
9,500
2.3
172
Indonesian Through‑flow & Indian Ocean (Philippines → Cape Agulhas)
7,800
2.2
147
South Atlantic (Cape Agulhas → Caribbean)
5,200
1.9
114
North Atlantic / Gulf Stream (Caribbean → Azores)
3,800
2.5
63
Return to Hawaii (via Panama)
4,200
2.1
83
Total
30,500
–
≈ 579
Distances are rounded and include modest detours to stay clear of the Roaring Forties/Furious Fifties. The actual path length around the globe at low latitudes is ≈ 25 – 26 k mi; the extra ~4 k mi comes from detours (e.g., Indonesian archipelago, Panama Canal).
5. Delays from Tropical Cyclones
Western North Pacific (Philippines‑Japan): Typhoon season June‑Nov. We assume a ~2‑week wait if we must pass through the region during peak months (July‑Sept). ≈ 14 days.
North Atlantic / Caribbean: Hurricane season June‑Nov. A 2‑week buffer is prudent when crossing the Caribbean in late summer. ≈ 14 days.
South‑west Pacific (Nov‑Apr): Minimal impact on our low‑latitude route; no extra wait is assumed.
Total assumed delay ≈ 28 days (≈ 1 month). Adding this to the pure sailing time gives:
Estimated total circumnavigation time:
≈ 579 days (sailing) + 28 days (weather‑avoidance) ≈ 607 days, i.e. ≈ 1.66 years (≈ 1 year 8 months).
6. Sensitivity – What if the Kite Works More (or Less)?
Kite‑hours per day
Avg. speed (mph)
Sailing days (no delays)
Total calendar days (incl. 28‑day weather buffer)
6 h
1.8
≈ 680
≈ 708 days (≈ 1.9 yr)
8 h (base case)
2.1
≈ 579
≈ 607 days (≈ 1.66 yr)
10 h
2.4
≈ 506
≈ 534 days (≈ 1.46 yr)
Thus, depending on how often the wind aligns with our heading, the circumnavigation would likely take between 1.4 and 1.9 years.
7. Conclusions
A solar‑ and kite‑powered seastead can realistically maintain an average speed of about 2 mph when it can use the kite ~8 h per day.
With a low‑latitude west‑about route that avoids the Roaring Forties & Furious Fifties and stays below the 15‑ft wave guideline, the estimated sailing distance is roughly 30,000 mi (including modest detours).
Including ~1 month of lost time for tropical‑cyclone avoidance, a first circumnavigation would take about 1.5–2 years.
Better wind‑forecasting (Starlink) and judicious use of ocean currents could shave a few weeks, while prolonged spells of adverse weather could add similar time.
These numbers are engineering‑order‑of‑magnitude estimates. Real‑world performance will vary with seasonal weather patterns, exact wind‑angle windows, and the exact current‑assist encountered each day.