I had hoped, while I’m in Rome, to visit Tiber Island to see its walls, shaped like a ship and marked with signs of Aesclapius. Earlier interpretations took these ship-like walls and aesclapian markings as evidence of a roman custom of building hospital ships to accompany their fleets. I think nowadays the Tiber Island markings are interpreted as merely confirming that the island served as a site for medical activities–though not specifically maritime-related–in ancient times.
The International Red Cross, in its introduction to the topic of hospital ships in “Geneva Convention” documents, makes mention of a Roman ship “Aesclapius” as an indication of Roman naval medical activity. Given the advanced state of Roman army medicine, it seems not too ambitious an intellectual leap to assume–even if no actual ship carcass be extant–that Romans were similarly advanced in their provision of medical care to ocean-going military personnel. Those Tiber Island walls and symbols may indeed reflect, in “model”, the reality in Roman fleets.