The B18 is a short route in Port St Mary towards the southern end of the Isle of Man. It starts at a crossroads with the A29 and A31 on the northern end of the small town, maintaining priority from the A29 to the north. It then heads south along Station Road, past the shops and on to Bay View Road, although with houses built up along the shore side, there are only glimpses of the bay here and there. The route curves with the coast, coming to a T junction where the road ahead is no-entry. Traffic therefore has to turn round to the right onto Park Road which, rather bizarrely, is the B28. The B18 can be resumed by turning left onto Queens Road, at the far end of the short B28, and following it down to a small triangular green. A double left TOTSO across the northern end of the green leads onto Athol Street, then High Street heading north back to the No entry signs noted earlier.