Rockhopper is listed on the Alternative Investment Market of the London Stock Exchange.

[3][4] An update of the first appraisal drill (well 14/10-4) was released in March 2011 indicating a significant reservoir package with a downhole mini drill stem test flowing oil at better rates than in a September 2010 flow test on well 14/10-2.

[5] On 27 June 2011, the company announced that its second Sea Lion appraisal well (14/10-5) flowed at commercially viable rates.

Rockhopper will be fully funded on its share of the Sea Lion development through the contribution to costs and standby financing provided by Premier.

In 2023, Rockhopper (working with Tel Aviv-listed Navitas Petroleum) said it had been presented with a new development plan for its Sea Lion project, that aimed to cut costs, and proceed in phases.