The delays have been caused by speed restrictions on the Blackwater rail system used to haul coal to the port, the company said.
Despite the delays in the coal supply chain, the port is still expecting to load around 1 million tonne of coal per week while stocks are available, Gladstone Ports Chief Executive Leo Zussino said in an emailed statement.
The port has 17 coal vessels at anchor with a further 16 expected to arrive this week, the company said.
The impact of recent heavy rains and storms has created delays in the supply chain causing inconsistency in the port's ability to load, Zussino said.
The port has annual coal export capacity of 75 million tonnes. The majority of coal handled at the port is coking coal for export to steel manufacturers in Asia and Europe.
Some central Queensland mines are still experiencing difficulties due to the heavy rains, although others have resumed full operation, Zussino said.