There are slipways on the north side of Dublin Bay at Clontarf, Sutton and on the southside at Dun Laoghaire Harbour, and in Dalkey at Coliemore and Bulloch Harbours.

Dublin Bay is administered by a number of Government Departments, three local authorities and several statutory agencies. Dublin Port Company is in charge of navigation on the Bay.

Dublin Bay is approximately 70 sq kilometres or 7,000 hectares. The Bay is about 10 kilometres wide along its north-south base, and seven km in length east-west to its peak at the centre of the city of Dublin; stretching from Howth Head in the north to Dalkey Point in the south.

Dun Laoghaire Harbour on the southside of the Bay has an East and West Pier, each one kilometre long; this is one of the largest human-made harbours in the world. There also piers or walls at the entrance to the River Liffey at Dublin city known as the Great North and South Walls. Other harbours on the Bay include Bulloch Harbour and Coliemore Harbours both at Dalkey.

There are two marinas on Dublin Bay. Ireland's largest marina with over 800 berths is on the southern shore at Dun Laoghaire Harbour. The other is at Poolbeg Yacht and Boat Club on the River Liffey close to Dublin City.

Car and passenger Ferries operate from Dublin Port to the UK, Isle of Man and France. A passenger ferry operates from Dun Laoghaire Harbour to Howth as well as providing tourist voyages around the bay.

Dublin Bay has two Islands. Bull Island at Clontarf and Dalkey Island on the southern shore of the Bay.

The River Liffey flows through Dublin city and into the Bay. Its tributaries include the River Dodder, the River Poddle and the River Camac.

Dollymount, Burrow and Seapoint beaches

Approximately 1,500 boats from small dinghies to motorboats to ocean-going yachts. The vast majority, over 1,000, are moored at Dun Laoghaire Harbour which is Ireland's boating capital.

In 1981, UNESCO recognised the importance of Dublin Bay by designating North Bull Island as a Biosphere because of its rare and internationally important habitats and species of wildlife. To support sustainable development, UNESCO’s concept of a Biosphere has evolved to include not just areas of ecological value but also the areas around them and the communities that live and work within these areas. There have since been additional international and national designations, covering much of Dublin Bay, to ensure the protection of its water quality and biodiversity. To fulfil these broader management aims for the ecosystem, the Biosphere was expanded in 2015. The Biosphere now covers Dublin Bay, reflecting its significant environmental, economic, cultural and tourism importance, and extends to over 300km² to include the bay, the shore and nearby residential areas.

On the Southside at Dun Laoghaire, there is the National Yacht Club, Royal St. George Yacht Club, Royal Irish Yacht Club and Dun Laoghaire Motor Yacht Club as well as Dublin Bay Sailing Club. In the city centre, there is Poolbeg Yacht and Boat Club. On the Northside of Dublin, there is Clontarf Yacht and Boat Club and Sutton Dinghy Club. While not on Dublin Bay, Howth Yacht Club is the major north Dublin Sailing centre.