Just a moment ago we launched our inflatables at the crack of dawn in the misty Arctic waters of Baffin Bay and headed straight for Cairn Energy's deepwater oil drilling rig, the Stena Don. A group of highly experienced climbers are now scaling the rig in order to stop the drilling and defend the Arctic. I'm writing this with a deep sense of pride in my fellow activists who are out there in near freezing conditions - taking action on behalf of all of us. They had to outrun the Danish navy and dodge special forces to get onto the rig but they've done it! And I'm writing this for you -- to make sure you are the first to know about what we're doing today and to say thanks for sticking with us since we left London three weeks ago.

We've been here next to Cairn Energy's deepwater drilling rig and their massive drill ship for 9 days now and we've seen enough to know that their operation must be stopped. We didn't just come here to take pictures - although some of the ones Will has taken have rocked the media and gone around the world - because it's now obvious that what they're doing here is madness. They are taking massive risks - with the Arctic, with our climate and with our future.

Many people know what Cairn Energy is up to now that we've come here and exposed it. But exposing it isn't enough. People get outraged but then they forget about it and move on with their lives and become distracted by the next piece of interesting news - we're all guilty of that sometimes. We're taking action today because we simply can't sit around waiting for an accident to happen here like in the Gulf of Mexico and we can't allow our climate to be affected any more than it already is. We all know we need to protect our planet from the worst effects of global warming but that's going to be a hell of a lot more difficult if Cairn finds oil here and all the big oil companies rush in to claim their stake in the deep waters off Greenland.

And so my friends - this is it. Today is the day we've all been waiting for - the reason we left London three weeks ago and the reason we've been keeping it all a bit low key until now. While our climbers are doing their absolute best to hold their occupation of the oil rig for as long as possible, everyone on the Esperanza is backing them and we're hauling ass to make sure the images and video footage go out as far as possible. But there are limits to what we can do here in the Arctic - and with the help of our friends back on land. There's only so much we can say in a press release and tell journalists over the phone… but on the internet - with your help - we can really make this action count. We can spread the story to all of our contacts and ask them to do the same. We can urge them all to write to Bill Gammell, Cairn Energy's CEO, and maybe - just maybe - we'll manage to convince him that he's making a big mistake. Maybe together we can make sure the world goes beyond oil and invests in a cleaner, safer future for all of us.

I've already taken a minute to send a letter to Bill today using the action form while Leila, our climate campaigner, has written him a personal open letter you can read here. Please join us by taking action today and inviting your friends to do the same.

- Lisa Vickers - on board the Esperanza