Finding the Roman navy through the army's logistics

How many genuinely professional navies do we know about in antiquity?

The evidence is thinner than for armies, but operational and supply evidence shows that ancient navies were often essential.

Ancient navies are easier to overlook because surviving writing often concentrates on armies. Operations and supply movements can expose their indispensability: if an army's supplies arrived somewhere by sea, a naval system made that possible. The exchange models how to infer naval activity without claiming the source record is fuller than it is.