Two ports, two roles
The Port of Havana grew up inside a sheltered bay right beside the old city, which is part of its charm but also a constraint. Space around the historic waterfront is limited, and the harbour is woven into a dense urban and heritage setting.
Mariel, by contrast, was developed as a purpose-built, deepwater facility with a modern container terminal that opened around 2014. Where Havana carries centuries of history, Mariel was designed for the scale and depth that large modern container ships require.
Why container traffic moved west
As global shipping shifted toward ever-larger container vessels, a deepwater port with room to grow became increasingly valuable. Mariel's terminal offered the depth and layout suited to that traffic, and much of the containerised cargo that once passed through Havana moved there after it opened.
This was a matter of matching cargo to the right facility rather than one port simply replacing the other. Heavy box traffic gravitated to Mariel's modern infrastructure, easing pressure on Havana's constrained and heritage-sensitive waterfront.
What Havana does now
With much of the container business handled at Mariel, the Port of Havana concentrates on cruise calls at the Sierra Maestra terminal, general and coastal cargo, and the everyday bay ferries. Its position beside Old Havana makes it especially well suited to passenger traffic.
So the relationship between the two ports is complementary. Mariel handles the deepwater container flows that need space and depth, while Havana keeps its role as the historic, city-centre harbour and a gateway for visitors arriving by sea.
Two ports, one coastline
Sitting relatively close together on Cuba's north coast, Havana and Mariel are best understood as parts of a single system rather than rivals. A country benefits from having both a modern deepwater cargo gateway and a historic passenger and coastal harbour, each doing what it is suited to.
For anyone studying Cuban shipping, the lesson is to match the question to the right port. Queries about large container flows point toward Mariel, while questions about cruise arrivals, city-centre access and the bay's heritage point back to Havana. Knowing which is which avoids the common confusion of treating the two harbours as interchangeable.