While the crew on Geronimo are struggling with the elements in the Southern Ocean, Team Cheyenne contemplate the repair of their toilet seat

I am sure it was designed by responsible engineers, who probably calculated test case loads of up to 100kg or so, based on static load, added a safety factor, and called it good. What they did not count on is the dynamic load of a seated body rising and falling through about 3m. The resultant compression on the seat when the dynamic force of the falling body is taken into account must exceed their wildest imaginings.

Ours, on the starboard side, started developing stress cracks in the Southern Ocean. As we charge up the south-east trades, the bows chopping the whitecaps like twin cleavers in the hands of a demon butcher, sitting on the toilet is a major feat. As the bow drops, one is suddenly weightless, suspended in space like an astronaut. Then the bow crashes into the trough, and gravity suddenly resumes its calling with interest, and one compresses into the circumference of the plastic ring separating flesh from raw porcelain.

We have, we hope, another five days of this punishing sailing, and the seat, well, it may join the cooking gas, the Mars bars, and the porridge on the list of things we will have to live without, unless Mike finds the time to have a go at it with some carbonfibre and paste.

This is the ultimate extreme sport, from which other sports can only borrow the name. Geographically, it takes us to the ends of the earth. Climatologically, in just over a week we have travelled from Antarctica to the Equator. Last week I was wearing four layers of underwear. Tonight, I am boiling in one. Two nights ago, we were drifting on lifeless seas. Last night, reefed and storm jibbed, we struggled to hang on as Cheyenne rocketed over the waves at speeds in the high 20s. Today, back to fighting the calm as the Doldrums loom. As I write these lines, a sudden squall has driven the wind speed from 18kts to 28kts, and it will surely fall to 10 before I finish the paragraph.

And it is long. Sixty odd days is a long time to be continually engaged in a sporting event which offers no opportunity for relief. We are 100 percent occupied with extremes.

It is hard to write while bouncing this much. Shortly I will be on watch. The feel of the steering wheel in your hands calms the motion. You are now the shaker, not the shaken.