As well as the hulls and their contents other objects scattered around the site were also recovered, including bronze and marble ornaments, tiles and utensils. Close examination disclosed that both ships had been sheathed in three layers of lead sheeting and the topsides were protected by paint and tarred wool. They were steered by 37 foot long quarter oars, with the larger ship using a total of four; two off each quarter and two from the shoulders, presumably to assist when manoeuvring.
  As a result of the weight of bronze and marble ornamentation, plus damage during earlier salvage attempts, the superstructures had collapsed, leaving their exact function open to debate.
  One theory has it that the barges were playthings of the mad emperor Caligula only to become redundant under the more sedate leadership of Claudius. It is also possible that they were floating temples, possibly honouring the Egyptian mothergoddess Isis.
  But there can be very little doubt that Caligula was in some way involved because a lead pipe found on one of the wrecks read; ‘Property of Gaius Caesar Augustus Germanicus’. This was Caligula’s full name and he ruled from AD 37 to AD 41. This probable period of their building is also reinforced by the dates on a number of tiles taken from the wrecks.
  Of considerable technical interest was the discovery of a pair of turntables which revolved on small wheels arranged around a circle. These may have been rotating bases for statues, giving credence to the floating temple theory. Whatever their true purpose, they were proof positive that frictionless bearings had been designed and used long before Leonardo da Vinci envisioned similar devices 16 centuries later.
  Also found on board were a remarkable bilge pump that worked like a modern bucket dredge and two anchors, one of oak with iron-tipped flukes and a stock of lead (possibly lead sheathed) and the other of iron and timber with a folding stock of a type not seen again until the 18th century.
  These remarkable ships have largely been ignored by history, possibly because they were destroyed during World War II.
  During the German retreat, troops burned 80,000 books and manuscripts of the Royal Society of Naples and then similarly destroyed the two Nemi Ships. This vindictive behaviour may have been pay-back for the Italian capitulation or just a few troops venting their anger; but either away it was an unforgivable act of vandalism that robbed the world of two of its most extraordinary maritime artefacts.
  Today, at Lake Nemi, about 30 kilometres south of Rome, they are remembered in a small museum containing one fi fth scale models plus a few of the original relics.