Norway's GC Rieber Shipping has extended an OCV charter in West Africa.
The 11,800-gt Polar Onyx (built 2014) will continue operating in the region for an unnamed charterer until the end of August.
It had entered into a four-month time charter in March.
There are more than two months of options with the contract.
Last July, Rieber won a deal for the vessel in Angola.
