At 14.53 GMT on Saturday Roxy and I crossed the Equator and entered the southern hemisphere - my third crossing on Roxy and my sixth in total. It is a significant passage for me because the "real" tour of the globe is done around the bottom of the world, in the south.

For sailors, the passage across the Equator is an opportunity to worship Neptune – our "king" - and say thank you for keeping us safe. A sailor’s first Equator crossing is a key moment in their life and the "equator virgins" must be initiated. This ceremony varies from crew to crew but is highly respected and normally (quite rightly) feared by those to be initiated.

For my first crossing ten years ago I was on board the maxi catamaran Royal and Sun Alliance on our all-female crew round-the-world record attempt. I remember the day very well, and also the few days leading up to it because there was some kind of "goo" being prepared by those who were not on their first crossing. The goo consisted mostly of freeze-dried food leftovers. At the moment of crossing there was a great calamity because Neptune himself had come on board (in the form of one of the crewmate). He was to conduct a kangaroo court against the "equator virgins". You can imagine the rest. Being one of the youngest on board (24) was probably not in my favour. It took a lot of washing to remove the goo and several days before the smell had gone.

My following equator crossings were a lot less grand, but all the same, very memorable. The second time I was alone, on the Mini Transat race. I was so tired and so grateful to be out of what had been a particularly difficult Doldrums that I probably would have kissed Neptune, goo and all. Strangely enough, he did not make an appearance that time, but instead I offered him my last coveted triangles of Toblerone, as well as the traditional champagne.

The chocolate offerings continued, although last year I was thwarted in my actions by Jeanne Gregoire, my chocolate-loving French co-skipper. She was horrified that I should throw such delicacy over the side (admittedly we were again running short on chocolate supplies) and banned me from making my traditional offering. At the same time, we were being caught up by the guys behind because of a terrible wind direction. Jeanne realised that Neptune was treating us badly because he had not had his usual ration of chocolate from me. When I came on watch the next hour I found Jeanne desperately throwing her chocolate into the sea. The wind consequently turned in our favour and we safely reached the finish line in front of our rivals.

Saturday's ceremony for Neptune was the usual offering of champagne, plus a bar (minus two squares for me) of Cadbury's Caramel. I also offered my flowers that friends had given me at the start. I have never done so before, but I thought that this time I will use my champagne bottle to send a message from Roxy.

After champagne, I was busy trimming the sails, and I hadn't noticed that Lucky and Foxy (my lucky duck and his flamingo girlfriend) had pinched the rest of the champagne and were finishing it off. They weren't feeling too good, being in the "wrong" hemisphere and all that. Thankfully, the champagne has worn off and I have managed to persuade them back to their home at the chart table, where I can keep an eye on them.

After Roxy and I celebrated with Neptune, I returned to my navigation and strategy. This, too, is affected by the change of hemisphere because, owing to the laws of Coriolis, the winds turn in the opposite direction. Thus, the winds turn anticlockwise around a high pressure and clockwise around a low one. That is something I must get used to because I will be in the south for two months. It will be summer for us, which is an important plus because the nights will become shorter and the icebergs and storms move farther south. We should be able to see the Southern Cross - a famous star constellation - but unfortunately I forgot my book of stars, so if someone could describe where to look and what to look for I'd be very grateful.

It is funny to think that next time I cross the Equator with Roxy I will have sailed effectively around the bottom of the world and will be on my way back home. It makes me wonder what my feelings will be then and how different my view will be of my adventure. Really soon it will be no more warmth, shower or bikini onboard Roxy and for a while. The south brings with it the relentless storms of the Southern Ocean, the constant thrashing of big seas and the threat of hitting an iceberg. These are only a few of the obstacles that the Vendee Globe fleet will have to endure in the coming weeks. It is my first time on board Roxy in the Southern Ocean, but as a two-times winner of this race, Roxy knows her way around and I have full confidence in her not letting the leading pack slip out of our hands.