On behalf of the City Governments of Oslo and Rotterdam, Menon Economics has prepared this report comparing key characteristics, strengths, and challenges of the maritime clusters in the Oslo and Rotterdam regions. The analysis is based on data from the Leading Maritime Cities (LMC) reports published between 2019 and 2024, combining objective indicators with expert assessments from 190 maritime professionals worldwide. Particular emphasis is placed on developments relevant to the green transition. The report also points to opportunities for closer collaboration between Oslo and Rotterdam, building on shared ambitions and complementary strengths.