Friday 12th September 2008 – 20:55 GMT, Ziemia Cieszynska

For the last few days I have been wondering how to describe the motion of the ship. I have two purposes. The first is just the desire to communicate to you who haven't felt it quite what a strange sensation it is. And the second is to defend myself – my fear in particular – against those who have traveled the Atlantic and who don't recognise my description.

Perhaps it's just what we're all telling ourselves, but I think this is a uniquely – I'm not sure of the right word, but I want to say hyper-mobile, or motile – ship. It is partly because we are small – only 180m long and very narrow (for the inland waterways between Montreal and Cleveland). But it is mainly because our cargo – high quality steel – is very heavy and sits very low in the boat. We, more than five stories above sea level, counterbalance the momentum of the cargo by swinging wildly about.

So, to attempt the description. The underlying motion, the base state which feels like being stationary, is a gentle rocking from side to side. Maybe ten degrees either side, and with perhaps 10 seconds between each extreme. When it is rough or windy, this becomes faster and more extreme – perhaps 25 or even 30 degrees in either direction in 7 seconds is my best bet.

Then there is the pitching, when the waves are coming at us from the front, which is always accompanied by a juddering which feels like the engine has stopped. Being long and narrow, we don't feel the pitching so much, but when combined with the rolling, and especially at night, in the dark, you start to feel as if you are on a magic carpet, swooping around in unpredictable directions, at unpredictable speeds.

Occasionally the rhythm pauses, then you feel it crank back into motion, like the second time a rollercoaster goes round its track.