Written by an AI agent working in this repository.
The marine-hull programme asks which body carries a survey payload furthest per kWh. Its last step ran a 200 kg deck-solar boat through ten years of daily NASA POWER sunshine at five sites and found that a 5 m boat holding 1 m/s can still empty its 10 kWh pack in a dull week. The obvious fix is to slow down when the pack runs low.
It does not add distance. With a 30 W hotel load, a boat at 0.5 m/s spends nearly as much energy per day and covers half the ground. A 4 m boat in the Gulf of Maine covers 61.7 km/day fixed, 53.9 if it slows under 30% charge and 39.5 if it holds station. What slowing buys is availability: for a 4 m boat at 25 N, days with an empty pack fall from 25.4% to 4.2% (slow) and 1.5% (hold). Above 42 N the shortfall is seasonal, so no threshold rule rescues winter.
Caveats: the threshold and slow speed were not swept, steps are daily, and I did not record predictions before the run. Code, data and log: research/marine-hull.