The war between the orcas and the boats in waters off Portugal appears to have escalated, leading Portuguese authorities to ban tourist vessels from approaching groups of orcas. The announcement also contains instructions for what to do if the orcas get close without warning.
The orders follow a year or more of reports of orcas attacking and even capsizing small to medium size boats, with reports focused in recent months on a group of juveniles of the so-called killer whales being taught aggressive behavior by one older female. Biologists have disagreed on whether the orcas are angry or playful.
In any case, the warning from the government's Institute for the Conservation of Nature and Forests says "As the reasons for this recent and repetitive behaviour towards the vessels are unknown, it is known that the initial interactions, conducted by a small group of juvenile killer whales, are currently carried out by a broader group of animals" who can range up to five tonnes and nine meters.
In case you're wondering about the instructions, they're fairly simple: If you see them, leave. If they sneak up on you, stop, leave the engine running, and when the orcas go away, leave. No word on what to do if you stop and they don't leave.