It was scarier than I thought it would be to be stuck hanging upside-down inside the cabin, with green water lapping at the hatches, creaks and groans coming from the boat, simply waiting for it to self-right again.

With BBC Points West looking on, we capsized the boat three times in Bristol Harbour with the help of Andy and his wonderful team of volunteers on MShed’s crane, as well as the Harbourmaster’s boat.

The first attempt was just to see what would happen if we capsized the empty, unballasted boat in flat water. She lay very comfortably upside-down, making no attempt to self-right.

Secondly, I got into the cabin and strapped into my harness to be capsized – again unballasted. The boat was more unstable, but still wouldn’t self-right, even after a good four minutes of struggling.

Third time lucky – we put 50kg of coal into the boat as ballast (the only thing we had to hand that was heavy enough), strapped me inside again, and capsized her. Almost immediately, she came round again.

Conclusion: ballast is very important if you don’t want to be trapped upside-down in your cabin in the middle of the Pacific!

BBC Points West coverage of the tests (with apologies to every other European crew at the end there!)