Douarnenez revolves around its port: the town and the port are one. There are also workplaces, factories and homes. On the hill, all the roads slope down to the port of Rosmeur. The alleys and streets are just as busy with work as the docks.

The local geography has shaped the town, where a natural harbour was initially used to moor a few boats. Engineers and technicians then added a simple mole and some slipways. These enhanced the natural shelter used for stopovers. They remained unchanged until the land reclamation work in the 1950s.
In 1911, the port had up to 800 sardine luggers. These working sailboats were particularly simple and efficient.

In response to the uncertainties of sardine fishing and economic imperatives, fishermen turned to other types of fishing: drift net fishing for sardines, ray in winter, and line fishing or drift net fishing for mackerel in spring. In summer, they all fished for sardines using gillnets.
With 4560 registered seamen out of a population of 15,000 in 1910, the seafaring population set the rhythm for life in the town.