All-female eXXpedition crew sails round Britain to highlight plastic in the oceans

In a few hours I'll be heading out to sea with 13 strangers on a 72-ft yacht called Sea Dragon.

It's an all-female crew and we plan to sail around the UK in 30 days.

The point of the eXXpedition voyage is to raise awareness around the growing problem of plastics in our oceans.

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As we go, we'll be collecting water samples to measure for micro-plastics and other toxic chemicals, as well as hold events in the various ports we sail to: Cardiff, Belfast, Arran, Stornaway, Edinburgh, London and Plymouth.

It's likely to be quite challenging and for me there will be an added complication because I'm filming.

Usually I have a camera person with me but I'll be leaving them behind this time because there is only room for one Sky guest on board.

Apart from these technical demands there is a whole host of other things to deal with: almost inevitable seasickness, getting cold, tired, wet and hungry as we work in shifts through the night to keep Sea Dragon on course.

And common sense dictates that there may be the odd bit of tension on board.

Also, a few of us - including me - can't really sail.

What could possibly go wrong?

I've been given life jacket number 13, which I'm hoping is not an omen.

But I think we'll be more than okay.

Luckily, this crew of interesting women seem pretty well equipped to handle the hardships and sail for an important cause.

Our skipper Diane is fantastically experienced and everyone in her crew has been chosen for their diverse skills, ages and approaches to life.

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On board, there is an artist, an activist, a former Silicon Valley whizz kid, a fish buyer for a major supermarket chain, an undergraduate marine scientist, and many more.

But the most important point for me is that this voyage is worth every challenge that comes with it.

We are poisoning our oceans... and so we are poisoning ourselves.

It has to stop.

As far as I'm concerned, anything that increases awareness of this merits going the extra (nautical) mile.

As the saying goes: "We all live downstream."