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 is one of three major bases of the Royal Navy today. The presence of large numbers of small watercraft are a challenge and hazard to the warships using the naval base and dockyard. Navigation on the waterway is controlled by the Queen's Harbour Master for Plymouth.
^Gover, J.E.B., Mawer, A. & Stenton, F.M (1931). "The Place-Names of Devon". English Place-Name Society. Vol viii. Part I. (Cambridge University Press): 20.CS1 maint: Multiple names: authors list (link)