The name first appears as ryver of Hamose in 1588 and it originally most likely applied just to a creek of the estuary that led up to the manor of Ham, north of the present-day Devonport Dockyard. The name evidently later came to be used for the estuary's main channel. The ose element possibly derives from Old Englishwāse meaning 'mud' (as in 'ooze') – the creek consisting of mud-banks at low tide., although this is not confirmed.
The Hamoaze flows past Devonport Dockyard, which belongs to the Royal Navy. The presence of large numbers of small watercraft are a challenge and hazard to the warships using the naval base and dockyard.