Reuters reports that Debmarine's revenue also dropped 5% to $427 million, while royalties and tax to the government eased 6% to $137.2 million.
Debmarine Namibia received $375 million to build a new diamond mining vessel from five African commercial banks.
Company chief executive Otto Shikongo was quoted as saying that work on the ship was progressing well and is expected to be completed in the third quarter of 2021.
He said production from the vessel is expected to commence during the second quarter of 2022.
The ship, known as the AMV3, was expected to add 500 000 carats of annual production.
Mathew Nyaungwa, Editor in Chief of the African Bureau, Rough&Polished
Namibia deals heavy blow to mining speculators
Namibia will bar locals who own mineral exploration licences from selling to foreigners, in a bid to discourage speculation in the sector, according to a news report citing a senior government official.
Mines and Energy Minister Tom Alweendo said that Namibian mining exploration licence holders would be required to retain at least a 15% stake in any mining venture effective April 1.
"For a Namibian to sell their entire stake in an exploration licence means they are not interested in mining but just want to make money," Alweendo was quoted as saying.
"I don't want Namibians to say that they have not been given opportunities."
Namibia previously required companies seeking new exploration licences to have a 20% Black Namibian representation in management.
The policy was scratched in 2018 after critics said the policy was discouraging foreign investment.
Chamber of Mines chief executive Veston Malango told the news agency that the new policy would not affect any foreign companies' exploration licences.
Mathew Nyaungwa, Editor in Chief of the African Bureau, Rough&Polished