Anchored to the Isola Corallo © Greenpeace/NovisSo despite several requests to leave Dumai, we haven't left (even though the harbour master visited the ship this afternoon and turned out to be a really nice guy). The reason for that is that we have a bigger and much more significant target in our sights. Now it's arrived and the Esperanza's crew have swung into action once more, and another anchor chain occupation is under way.

We've been waiting a few days for the Isola Corallo to turn up, and at one point a spelling mistake in the ship's name made the researchers wonder whether it even existed. It's time of arrival has slipped later and later but around 7.30pm it finally dropped its anchor.

We headed out into the dark and once more made for the anchor chain. The designated climber scrambled up the chain but, unlike with the Gran Couva, the crew showed very little interest. A couple of heads peered over the side, but their captain had already been informed what we were up to. Plus the crew were probably more interested in shore leave, but I imagine that will change.

So why this ship in particular? The Corallo is another large tanker due to pick up a consignment of palm oil and, like the Gran Couva, it's bound for Rotterdam. We've been waiting for this ship to turn up because the palm oil it's collecting belongs to Sinar Mas, which is not just the largest palm oil company in Indonesia, but also the largest in pulpwood and paper too. It was Sinar Mas that was responsible for the large-scale forest clearance which the helicopter team saw near Jayapura in Papua several weeks ago, and more recently in the Kampar peninsula.

As a member of the Roundtable on Sustainable Palm Oil, Sinar Mas is supposed to be improving the environmental and social welfare standards of its operations. But as we've seen, like many other RSPO members Sinar Mas is still tearing up forests across Indonesia as it pushes an aggressive expansion policy.

I explained last week that the RSPO is a self-regulating industry body which, instead of striving to make the industry more responsible, is actually helping to cover up some of its worst practices. By creating the illusion that its members are not clearing forests, cheating indigenous people out of their land and so on, it's justifies the industry's continuing expansion, which means plantations growing in place of virgin forest and peatland.

This week, we've seen the first shipments arrive in Europe of palm oil certified as 'sustainable' by the RSPO, produced by United Plantations in Malaysia. But even without a feeble set of criteria the company had to meet for its certificate, it's still hacking away at forests in Indonesia and shows no signs of stopping, throwing the notion of 'sustainable' palm oil in serious doubt.

The RSPO is holding its annual meeting in Bali next week, so all our recent actions have been timed to throw this greenwash into sharp relief. If the RSPO isn't capable of bringing its members to heel (or simply doesn't want to), then something else needs to be done.

The governor of Riau province - home to Dumai and vast plantations of palm oil and acacia for pulpwood and paper - has already issued a decree for a moratorium on deforestation here. It needs authorisation from the national government to become a reality, and the moratorium has to be extended across Indonesia. Don't forget you can write to Susilo Bambang Yudhoyono, president of Indonesia, asking him for just such a moratorium to be put in place before it's too late.

It's going to be another night on the chain for our dedicated climber, but for the time being things look quiet. However, the Corallo will want to load up with palm oil soon and then things will get really interesting. Don't forget you can get updates quickly from Twitter as well.