Guernsey Harbours manages and upkeeps a sizeable waterfront estate at St Peter Port and St Sampson on behalf of the States of Guernsey. It is a mixture of land areas, buildings, slipways, pontoons, piers and structures.
Much of the estate is used for commercial purposes by both the States of Guernsey and its tenants. There are also significant areas of public realm including public car parks, walkways and viewing points. In addition, the Castle Breakwater and the seawalls provide the towns with protection from adverse weather and tidal conditions.