The films get this wrong. A storm at sea does not arrive out of a clear sky. You watch it coming for three days on a weather routing chart, and the interesting decisions are all made before the first big wave.
You see it coming
Ships receive weather routing — forecast charts, wave height predictions and often a recommended track from a shore-based service. Three days out, the low is a set of isobars on a chart and a number: significant wave height, six metres, rising.
So the conversation starts early. Alter course north and add a day. Slow down and let it pass ahead. Hold course and accept a bad thirty-six hours. Each option has a cost, and at least one party — the charterer — is paying attention to the schedule.
Securing the ship
A day out, the Chief Officer takes the deck crew round everything that could move. Lashings re-tensioned. Deck cargo checked. Hatches and vents secured. Anchors given extra lashings, because an anchor that works loose in a heavy sea will destroy the bow.
Below, the same: fridges latched, loose gear stowed, the galley told what is coming. The engineers secure the machinery spaces and prepare for the main engine to be loaded and unloaded violently as the propeller comes clear of the water and races.
What it is actually like
A loaded ship in a big sea does not crash about. It moves slowly and enormously, with a period of ten or twelve seconds, and the scale of it is the thing that surprises people. You are not being thrown around. You are being lifted and set down by something the size of a hill.
What wears you out is that it never stops. Every task takes three times as long because one hand is always holding something. Nobody sleeps properly. You wedge yourself into the bunk with a lifejacket under the mattress and doze in twenty-minute pieces. After two days of that, the crew are tired in a way that is itself a safety problem.
FROM THE BRIDGEYou do not fight weather. You reduce speed, adjust heading, and make the ship as comfortable as a hundred thousand tonnes of steel can be made. Then you wait.
The decisions on the bridge
Two things are managed continuously: heading relative to the sea, and speed. Head-on into a big swell the bow slams and the ship pitches; beam-on she rolls, which is worse and can be dangerous. So you take the sea on the bow, at an angle, and you accept that this is not where you wanted to go.
Speed comes down — partly for comfort, mostly to stop the bow burying and to reduce slamming loads on the hull. Some ships heave to and simply hold position into the weather for a day. That is not defeat. It is the correct answer when the alternative risks damage.
Afterwards
It ends less dramatically than it starts. The swell drops over about twelve hours, the ship steadies, and the first proper hot meal in two days appears. Then comes the damage inspection: lashings, hatch covers, deck fittings, and any cargo that shifted.
And then the report — a heavy weather entry in the deck log, a note to the office, photographs of anything damaged. If a claim follows months later, that log entry is the evidence. Which is why, at the worst point of a bad night, somebody is still writing down wind force, sea state and barometric pressure every hour.