In the picture, the white marble head of the god Serapis is hauled from the sea in the Bay of Aboukir. Buried in deep silt lie statues, inscriptions, mosaics, jewellery, coins, fragments of a lost world. "With Herakleion, in particular, we have an intact city, frozen in time," says Mr Goddio. Although recovery conditions are tricky, the urban edifices remain pristine, just as they slid into the sea more than 1,000 years ago, with relics dating back another 1,500 years.
The three cities were established before 600BC at a point where a now-vanished branch of the Nile (the Canopic Nile) met the shallow shore of the Mediterranean Sea.
Before the establishment of Alexandria, Menouthis and Herakleion were famous in ancient texts for their wealth and trading importance. Their location had never previously been confirmed, nor their disappearance explained. Canopus was named after the mythical helmsman of Menelaos, husband of Helen of Troy, who was said to have been bitten by a viper on the shores of Egypt and turned into a god. The Ptolemaic rulers of Egypt were keen to confer such mythic legitimacy on their rule and built several temples at Canopus, the grandest of which was dedicated to Serapis.
Ptolemy I, founder of the dynasty, was one of Alexander the Great's generas. In 323BC, when Alexander died, Ptolemy gained Egypt as his share of the empire and created the new god Serapis as a fusion of the old Egyptian gods Osiris and Apis, both of whom had strong cult followings in the old Egypt. The temple of Serapis attracted travellers from all over the ancient world, including Greek writer Strabo in 26BC, who recorded the "sheer enjoyment" to be found in the town of Canopus.
Later generations turned against pagan revellers. In the fourth century AD the temples were broken down by Christians angry at idolatry and seeking revenge for the previous persecution of Christians, among them St Cyr, whose name gives the Bay of Aboukir its modern name (Father Cyr). Aboukir is Arabic, and in the middle of the seventh century AD the Muslims conquered Egypt.
Catastrophic events plunged the three settlements beneath the sea, perhaps in AD365 or AD746 when major earthquakes and tsunamis (tidal waves) hit the area. And there they have remained, until Franck Goddio tracked them down through research methods ranging from the most old-fashioned library detective work to using the most modern seismic reflecting monitors, which map patterns in the ocean floor.
Raising any but the prime pieces will be difficult, but Mr Goddio has other plans. Off the shores of modern Alexandria, he says, it is "thinkable, and feasible, to establish an underwater museum".
So, if you want to travel far beyond the confines of everyday life, in 10 years' time you may be able to put on a scuba suit and swim back in time.
Victoria Neumark. Photograph by Christoph Gerigk.