One of the consequences of New World First Ferry Services Limited operating vessels which routinely emit black smoke can be seen in the cone of soot on the wall of the ferry pier, right next to the passenger hall:
Outlying Islands Ferry Pier 5 - to Cheung Chau.
New World First Ferry Services boat Xin Guo,
one of the many polluting vessels operated by this company, berthing at Pier 5.
Soot forming a smoke cone at Pier 5.
The gap below the smoke cone is the passenger hall.