Cruising / racing sailing yachts. Power-plant used for aux and manoeuvring rather than primary propulsion. Per-running-hour intensity and sail-assist fraction tell the story.
Formula
$$ \text{CO}2^\text{year} = \sum_j F_j \cdot C{f,j} $$
$$ \text{Intensity} = \frac{\text{CO}2 \cdot 1000}{h\text{engine}} $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $F_j$ | Mass of fuel $j$ | t | bunker log |
| $C_{f,j}$ | CO₂ factor | t CO₂ / t fuel | MEPC.364(79) |
| $Bench (Engine-run hours / year)$ | operational benchmark | h | operations log |
| $d_\text{op}$ | Operating days | d | operations log |
Sailing yachts typically emit 5–25 kg CO₂ per engine-hour depending on displacement and diesel size. Full-time sailing with battery-electric aux can zero this out; diesel-only sailboats on charter can burn more than expected due to generator loading.
Sources
- ISS - International Superyacht Society sustainability guide.
- IMO MEPC.364(79) - Cf conversion factors.