It runs as double track along the majority of its route north along the scenic east Antrim coastline from Belfast to the coastal seaport town of Larne, serving commuters and ferry passengers.

At Downshire bridge the line crosses the A2 road once more and from here north, it follows the coastline at low level, offering views over the lough towards County Down and the Copeland Islands.

Then north to Larne as single track, there are three intermediate halts, Ballycarry, Magheramorne, and Glynn, each serving villages en route.

On the coastal side, the peninsula of Islandmagee blocks views of Scotland, but forms the wildlife wetlands of Larne Lough.

Small sections of the track at the Larne end are built on causeways, forming ponds landside of the railway.

On weekdays, trains run half-hourly from Belfast Grand Central, with the outbound terminus alternating every half an hour between Larne Harbour and Whitehead.