Decisive

No messages here yet.

Safety messages the ship broadcast to everyone nearby over AIS, word for word, from the last 30 days. Written by the crew; most ships rarely send them.

Heard

Ships send their position by radio (AIS) every few seconds to minutes. Receivers on land pick it up, so a ship far out at sea isn’t heard until it nears a coast.

Knots (kn)

How ships measure speed. 1 knot is 1.85 km/h or 1.15 mph, so 10 knots is about 19 km/h (12 mph).

Working, can’t move freely

What cable ships report while laying or repairing cable: they’re holding a line or a position and can’t easily get out of the way.

Stopped at sea

Engines on but not moving, often holding position while working.

Track on the map

Solid blue where the ship was heard. Grey dots where it went quiet for more than half an hour: an estimate of its route from where it was last heard to where it was heard again, following the usual sea lanes round any land. The real path isn’t known.

Turning

How fast the ship is changing direction, as it reports it: “holding course” when it isn’t. Only while it’s moving.

Messages from the ship

Short safety notices the crew broadcast to every ship nearby, such as asking others to keep clear while they work.

Heading / Facing

Which way the ship is moving, and which way its front points when it is stopped.

Draught

How deep the bottom of the ship sits below the water line.

IMO / MMSI

A ship’s permanent ID, and the number its radio uses. The MMSI’s first three digits show the country it’s registered in.

Doing / Heading to

Typed in by the crew, so it can be out of date. Cable ships often type an activity instead, like “CABLE OPS” (cable work at sea).