Ro-Pax Ferry CII
CII for Ro-Pax combination ferries. MEPC.337 Ro-Pax reference (a=7540, c=0.587), GT-based. Widest d-boundaries of any ship type (d4=1.41) to accommodate schedule-constrained operations where slow-steaming isn't an option.
Ship & voyage
Fuel
Many new Ro-Pax are LNG or LNG-hybrid (Stena, Finnlines, Viking Line).
Attained CII
13.701g CO₂ / (GT·nm)
Required CII
12.734g CO₂ / (GT·nm)
Rating
C
Moderate performance. Compliant.
Formula, assumptions, and limits
Ro-Pax d-boundaries: d1=0.72, d2=0.90, d3=1.12, d4=1.41. IMO acknowledged that Ro-Pax cannot practically slow-steam - the bands are generous but the absolute reduction curve still tightens at 11 %/year.