Not the three-word title of a Robert Ludlum thriller, but the strange movement of tidal currents around Ibiza harbour.
The captains of the high speed ferries which run to sister island Formentera have noticed a strange and potentially dangerous shifting of the sea currents at the mouth of the harbour since the new dyke was built.
Its construction has reduced the size of the mouth of the port by 66% and has therefore affected the flow of water. They say that under certain conditions, for example a storm from the south-east, the tides could prove dangerous and could even affect the make up of nearby beaches at Playa den Bossa and Es Cavallet!
Footnote: The new dyke has actually cost €48m, 25% more than originally envisaged.