Insights · Trade routes · Canals
Two artificial waterways carry a vast share of seaborne trade and, between them, set the dimensions of much of the world's fleet. The Panama Canal lifts ships over a mountain with locks; the Suez Canal cuts a sea-level channel through the desert. How each works — and why one of them nearly emptied in 2024.
Almost every figure in shipping — the length of a bulk carrier, the beam of a container ship, the draught of a tanker — is shaped somewhere by a canal. Two of them dominate: the Panama Canal, which shortcuts the journey between the Atlantic and Pacific, and the Suez Canal, which links the Mediterranean and the Red Sea and so connects Europe to Asia without rounding Africa. They solve the same problem — avoiding a long detour around a continent — in completely different ways.
The Panama Canal does not cut through at sea level. The land across the isthmus rises, so ships are lifted by a series of locks up to the level of Gatun Lake, carried across, and then lowered on the other side. Each lock is a chamber that floods or drains to raise or lower the vessel inside it. Because of this, the size of a ship that can transit is fixed not by the channel but by the lock chambers — which is why "Panamax" became one of the most important size words in shipping.
For most of the canal's history the limit was the original locks, defining a Panamax ship of roughly 294 m by 32 m. In 2016 the canal opened a third, much larger lane: the Neopanamax locks. These take vessels of up to around 366 metres in length, 49 metres in beam and 15.2 metres in draught — opening the canal to far larger container ships and gas carriers, and creating the newer Neopanamax class.
| Limit | Length | Beam | Draught |
|---|---|---|---|
| Panamax (original locks) | ~294 m | ~32.3 m | ~12 m |
| Neopanamax (2016 locks) | ~366 m | ~49 m | ~15.2 m |
One quirk of the lock design matters in dry years: the locks consume fresh water from Gatun Lake on every transit, so drought can force the canal authority to cut draught limits and daily transit slots — a constraint Suez never faces.
The Suez Canal works the opposite way. It runs through flat desert at sea level, so it needs no locks at all — a ship simply sails through. The channel is roughly 193 kilometres long, from Port Said on the Mediterranean to the city of Suez on the Red Sea. Its limit is the cut itself — its depth and width — rather than a lock chamber, which is why the canal has been repeatedly deepened and widened, and partly twinned, to take larger ships and two-way traffic. The size class it defines, Suezmax, is the largest tanker that can transit fully laden.
Between them, these canals have stamped their names onto the fleet. A ship is described as Panamax, Neopanamax or Suezmax precisely because it is built to slip through one of these passages. Add Capesize — the bulk carriers too big for either canal, which must round the Cape — and you have the backbone of how dry-bulk and tanker tonnage is classified. We set out the full taxonomy in ship types explained.
A canal does not just save a ship time. By fixing the maximum size of vessel that can pass, it quietly designs a large part of the world's fleet. On the Panama and Suez size classes
The Suez route is only valuable if it is safe. From late 2023, attacks on shipping in the Red Sea and the Bab-el-Mandeb strait led a large share of operators — container lines above all — to reroute around the Cape of Good Hope, adding thousands of miles and many days to the Asia–Europe voyage. The effect on Suez was dramatic: after a record year in 2023, the number of transits in 2024 roughly halved, with container traffic falling hardest. Vessels that would have taken the canal instead showed up on the long southern route or, in some cases, switched to Panama. It was a vivid demonstration that a chokepoint's throughput depends on geopolitics as much as geography.
A ship's dimensions and draught tell you which canals it can use, and its live track tells you which one it actually took — Suez, Panama or the long way round the Cape. When tankers reroute to avoid scrutiny rather than danger, the diversion can itself be a dark-activity signal. On Marifest you can search any of 97,000+ vessels in the registry, read the size class that fixes its route options, follow it on the live map where positions are available, and check its compliance standing. Every term used here is defined in the maritime glossary.
How Marifest uses it
A vessel's dimensions decide which canals it can use; its live track shows which one it chose. Marifest keeps both on the open file.
Length, beam and draught — the figures that decide Panamax, Neopanamax or Suezmax fit — sit on every vessel record.
Where AIS is available, the live map shows whether a ship took Suez, Panama or the long way round the Cape.
A tanker rerouting to avoid scrutiny rather than danger can be a dark-activity marker — part of the picture Marifest surfaces.
Size, position, flag and sanctions standing sit together, so a ship's route is always read in context.