Background: The shipping industry has grown spectacularly during the last 50 years transporting nowadays, approximately, the 80-90% of goods worldwide. However, maritime transport remains a highly inefficient industry. Only in the last 10-15 years has the industry started studying how to optimize navigation speeds and digitization is just entering ports. Consequently, institutions like the International Maritime Organization (IMO) are pressing towards the adoption of measures that increase the industry efficiency, like Just-In-Time (JIT) operations.Methods and Results: This paper shows why the Sea Traffic Management (STM) concept, based on stakeholder collaboration, is a JIT enabler. To do so, we analyze 1 year of navigation data of 33 ships, estimating the impact of JIT barriers on shipping and showing the benefits that the adoption of STM, with different maturity levels, could provide to the industry. Our evaluation shows that, only for containerships, STM can help reducing by 15-23% of fuel consumption and GHG emissions.