British Museum, London This frustrating show about the ‘lost worlds’ of the Nile Delta has too much Indiana Jones nonsense – and not enough genuine wonders

The shiny black statue of a woman from ancient Egypt who may as well be naked floats, without head, hands or feet, among blue walls, low lights and eerie recorded underwater noises. This sculpture may be the most erotic celebration of brother-sister incest ever chiselled. Of course, it’s not exactly a competitive field. Incest is not a mainstream artistic subject, except in the submerged ancient cities of Canopus and Thonis-Heracleion.

Drowned worlds: Egypt's lost cities Read more

This silken nude expresses a Greek-Egyptian king’s fond memories of his sister-wife. When Arsinoe II died in about 270 BC, Ptolemy II put up scores of statues of her. She became a cult figure, almost a goddess, for in keeping marriage in the family, the Ptolemaic dynasty imitated the incestuous Egyptian gods Osiris and Isis. The eventual descendent of Ptolemy and Arsinoe’s unions would be Cleopatra VII, who seduced Julius Caesar and Mark Antony, and brought the age of the pharaohs to a sleazy, bloody end.

Hollow gods and cold dead eyes fill Sunken Cities, the British Museum’s distinctly odd, frequently frustrating and ultimately dull exhibition about the “lost worlds” of two Greco-Egyptian cities, first discovered in 1933 on the Mediterranean seabed in the Nile Delta. There’s something charmless about these cities; a lack of humanity in their lifeless stones. The weird cult of Arsinoe typifies this.

Here are the fruits of a union between two declining cultures in cities that were backwaters of the human spirit, and the exhibition is a sad illustration of why archaeologists should beware of hyperbole. Canopus and Thonis-Heracleion are currently being excavated by divers and underwater archaeology sounds exciting. It is exciting – if you are there. But looking at the rescued objects in a museum once the barnacles are scraped off is another matter.

Facebook Twitter Pinterest Preservation problems … the head of a Cypriot statuette, late 4th-5th century BC. Photograph: Christoph Gerigk/Franck Goddio/Hilti Foundation

Here, they have to speak for themselves. But this exhibition patronises with Indiana Jones-style nonsense. A film and photographs, eerie lighting and obtrusive sound effects crank up the volume. Yet many of the wonders are not that wondrous. There are some unadorned stone boxes, and a lot of oxidised bronze ladles. As for the revelatory evidence of complex contacts between ancient Egypt and Greece that the exhibition promises, there is just an eyeful of a wine amphora and a damaged Greek perfume bottle.

There are a couple of very obvious problems with talking up these two submerged cities as if they were revelatory. One is that the art of Egypt has been collected since ancient times – later objects in the show are connected with the Roman emperor Hadrian, who created his own Egyptian temple in his villa at Tivoli. Western museums have been filled with Egyptian marvels for centuries, not least the British Museum, with its colossal head of Ramses II and the multilingual Rosetta Stone. New discoveries are more likely to add detail than change the overall picture of Egypt established by generations of archaeologists.

Facebook Twitter Pinterest Worn sockets that were their eyes ... a statue is excavated by divers at Thonis-Herak. Photograph: Christoph Gerigk/Goddio/Hilti Foundation

If Sunken Cities is starting to sound a bit boring, it’s partly because it fails to bring to life an age when Egyptian art was turning into a pastiche of itself, under Greek kings going slowly bonkers in the heat. In 332 BC, Alexander the Great conquered Egypt. When he died nine years later, his general Ptolemy created a dynasty that ruled Egypt for 300 years. What is sold as a creative mix of Greek beauty and the Egyptian sublime was a self-cannibalising culture that fed on the past until the Romans came along and pushed it over.

A colossal slab of red granite from Thonis-Heracleion is inscribed with an official text in both Greek letters and Egyptian hieroglyphs, very little of it legible because, as the catalogue concedes, it “has been badly damaged by erosion”. Well, that’s what happens when something lies on the sea bed for millennia. Full fathom five the Ptolemies lie: those are worn sockets that were their eyes.

The fundamental problem with this exhibition is that ancient materials, even stone, are preserved far worse by the sea than the hot sands of Egypt. There, the dry earth miraculously holds even organic matter in a time warp: papyri, shoes, wigs and of course the mummified dead themselves. The remains here are far more damaged, hence far less intimate, human and beautiful, than the painted faces and delicate wooden toys found in dry Egyptian sites such as Fayoum.

The curators compensate by adding works of art from dry-land locations such as Luxor, to fill out the patchy evidence from their supposed underwater wonderlands. There is a huge, haunting wooden statue of Serapis, a glitteringly spooky chamber full of stunning images of the god Osiris, and an unforgettably sinister statue of the hippopotamus god Taweret – but these truly memorable works were not found at the lost cities the show is supposed to be about and have been in museums for years.

Facebook Twitter Pinterest Incomplete picture ... bronze hieroglyphic inscription to Amasis II found at Thonis-Heracleion. Photograph: Christoph Gerigk/Franck Goddio/Hilti Foundation

There is nothing wrong with archaeology being unspectacular. Some of the most important excavations are. The problem with this exhibition is that it claims to be what it is not. The glamour Sunken Cities craves is that of Howard Carter opening the tomb of King Tut and peering into a chamber full of gold. The reality is more like the meat and potatoes approach to archaeology advocated by Flinders Petrie, who learned more about ancient Egypt from fragments of pot than Carter did from all that gold.

Why is the British Museum suddenly trying to play the phoney Carter game and dress up archaeology as an action movie? Leave that to sensationalist TV shows and give us honest encounters with the past.

• Sunken Cities: Egypt’s Lost Worlds is at the British Museum, London, 19 May-27 November.