Lost containers, derelicts and other things adrift
Written by seahazards · updated 2026-09-24 · numbers recounted nightly
Some of the hardest hazards to avoid are the ones nobody placed: containers washed off a deck in a storm, a yacht abandoned mid-ocean, a raft of fishing gear. They move, often low in the water, and each warning is only a snapshot.
Containers overboard
Containers are lost mostly in heavy weather, when stacks collapse or a ship rolls hard; a single incident can put dozens or hundreds into the sea. Many sink quickly. Others float for days or weeks, barely showing above the surface and returning little radar echo, which is why ships report them and coordinators warn about them.
A container warning usually gives the ship, the number lost and the position at the time, and later warnings report individual sightings. The number in the first message is what the ship reported then; later messages can revise it.
Containers are not the only cargo that ends up adrift. Logs washed off deck cargoes, lost fishing gear, fish aggregating devices and broken mooring buoys are reported the same way, as drifting objects with a position and a request to keep a lookout.
1,042 messages classified as drifting containers were issued from 1997 to 2026; the largest yearly count is 2014, with 67. Collection is incomplete between 2024-05 and 2026-08-17. Counts are messages, not incidents.
Derelicts
A derelict is a vessel afloat with no one aboard — left after a rescue, a dismasting or a storm. Yachts and fishing boats can drift for months, unlit and low in the water, and are reported again and again as ships pass them.
Because each report gives a new position, a derelict leaves a trail of warnings across an ocean. seahazards links those reports on its related-warnings pages and, for derelicts still in force, estimates where ocean currents and wind have probably carried them since.
5,527 messages use it, 4 of them in force now; most often in North Atlantic Ocean, Indian Ocean, North Pacific Ocean.
Why positions go stale
Wind and current carry a floating object several to tens of miles a day, so a warning's position is reliable only for as long as it takes to travel that far. The drift estimates on this site step the reported position forward with surface current (from the U.S. Navy's HYCOM ocean model) and a fraction of the wind, and draw a widening envelope around the result. They are estimates, not positions, and not for navigation or search and rescue.
The drifting objects atlas brings containers, derelicts and debris still in force together on one map.
13,064 messages use it, 5 of them in force now; most often in North Atlantic Ocean, South China Sea, North Pacific Ocean.