Why is it much, much worse for protesters to interfere with oil exploration at sea than on the land?

A couple of years ago I wrote this post about the attempts to stop Petrobras surveying for oil in the seas off East Cape.

There is a dispute out in the sea. The police must be able to arrest someone ... musn't they?

Here is what I understand to be happening at present on the seas far off the East Cape. A seismic testing vessel, the Orient Explorer, is under contract to Brazilian petrol giant Petrobras to conduct a survey of the Raukūmara Basin seabed.

As the United States shuts down deepwater oil drilling to get it back under control, New Zealand opens the door. Gerry Brownlee may not get much more mining on the conservation estate, but he can get it off-shore. How good is that?

Genial Gerry Brownlee was not ready to concede defeat when he appeared on TV3’s The Nation at the weekend, even though his plan for more mining in the conservation estate seems to