Approach and entry to Bangor Marina is made via Belfast Lough. The lough is busy with commercial traffic approaching and leaving Belfast docks, and the traffic includes many large and fast ferries. A sharp lookout is needed.
Tides within Belfast Lough basically run in and but with a definite anticlockwise set that could slow your approach to Bangor if following the South shore of the Lough four to one hours before HW Belfast. If following the South shore tidal flows will be in your favour from about one hour before high water Belfast to 2 hours after high water Belfast. See the animated flow diagram in "More Info" section.
Coming from the South leave the red can Briggs buoy (Fl(2)R.10s) on your port side, give Ballymacormick point a good offing, pass Ballyholme Bay, and make your approach to the Marina when it is bearing south (and you are directly to the north of it).
If coming from the North, pass Black Head with its lighthouse (see photo gallery), and give the Cloghan Jetty a good offing by leaving the green conical Cloghan Jetty buoy (Q.G), on your starboard side. The tide will be sweeping you quite strongly southwards towards the Marina if you make this approach five hours to two hours before high water Belfast (as opposed to inwards towards Belfast).
The closer approach to Bangor Marina is simple enough, between the North Breakwater (lit Iso.R.12s), and Pickie Breakwater, c/w large dolphin structure (lit 2F.G(vert)). This can be seen in the photo gallery, and is followed by a green pile beacon (Fl.G.3s). Leave to Starboard, make your turn to starboard leaving the smaller Central Pier to port, you are now in the marina.
Fishing vessels and other larger craft use the outer harbour between the North Pier and the Central Pier.