It is situated halfway between Cape Town and Port Elizabeth at Longitude 22º 08' E and Latitude 34º 08' S and is the smallest of the commercial harbours along the South African coast.
 
One of the most famous landmarks at Mossel Bay is the Post Office Tree, where seafarers from centuries ago posted letters home using a cleft in an ancient tree as a postbox. This signifies that ships called at Mossel Bay regularly for watering and other purposes.
 
Today Mossel Bay is an active harbour caterng for the fishing industry and with the developing oil industry, which began with Mossgas in the late 1980s. The port sees little other commercial activity and there hasn't been any other significant growth in the ensuing years.
 
The harbour has two offshore mooring buoys inside port limits, of which one is a marine tanker terminal single point mooring buoy used by feeder vessels from Durban and Cape Town.

Port Limitations:

The harbour entrance channel has a depth of -8m, while inside the harbour the maximum permissable draught is 6.5m. Ships anchoring outside port must keep clear of the approaches to the entrance channel. Pilotage is compulsory from a point 2 n.miles northeast of Cape St Blaize.
 
Inside the harbour vessels of up to 130m and a 6.5m draught can be accommodated at quay 4. There is a slipway for ship repair up to 200 tonnes.
 
The catenary buoy mooring caters for ships up to 32,000DWT with a maximum length of 204m and draught of 12m. Ship movements are permitted during daylight hours only. The second mooring is a single point mooring (SPM) connected to three hoses and is used primarily for the export of Mossgas products.
 
Mossel Bay is a common user port with ships worked on a first-come-first-served basis. Berthing is subject to wind and swell conditions.

Marine Craft:

Mossel Bay has a work boat/tug built in 1998 and named Arctic Tern with a bollard pull of 19t plus a mooring launch named Snipe, which is also used as a pilot boat and for the transfer of crew and other personnel.

Port Volumes:

During the 2015 calendar year Mossel Bay handled a total of 1050 vessels with a combined gross tonnage of 4,540,038-gt, of which South African trawlers constituted the majority.

In 2015 the port handled a total 2,518,316 tonnes of cargo, of which 2,474,522t was bulk cargo (almost entirely oil products) and 43,875t breakbulk. 
 
Imports amounted to 1,468,106t while exports totalled 1,050,290 tonnes. Mossel Bay does not handle containers.

Port Facilities:

The harbour of Mossel Bay caters mainly for fishing and service craft for the local oil industry and handles little other commercial cargo, and therefore has little in the way of sophisticated infrastructure. However the fishing industry provides an important economic boost to the Southern Cape and the local community, as has the oil industry.
 
An increasing number of ships for the emerging oil industry (several oil rigs operate off Mossel Bay) call at Mossel Bay. Supply vessels make use of two buoys anchored outside the port. In keeping with this industry a full diving service is available for underwater inspection, hull cleaning, salvage etc.
 
Bunkering is available at quays 2,3 and 5 and on the jetty. Ship chandling and stevedoring is available.