Rockhopper Exploration plc has filed a regulatory announcement providing an update on its acquisition of the OSX-1 floating production, storage and offloading vessel.

The company released the notification, headed "OSX-1 FPSO Acquisition Update," through the UK regulatory news service on 12 June 2025. The filing places the FPSO transaction formally on the public record for investors tracking Rockhopper's offshore development ambitions.

The OSX-1 is a floating production unit with a operating history in South American waters, where it served an offshore field development before being laid up. Rockhopper has been working to secure the vessel as a production solution for its portfolio.

What does the update cover?

The regulatory notice confirms the status of the purchase process for the vessel. Rockhopper issued it under its standard disclosure obligations as an AIM-listed company, meaning shareholders received the update alongside the wider market.

The announcement does three things for the investment case:

• Puts a dated, auditable marker on the FPSO acquisition timeline
• Confirms the transaction remains an active workstream for the company
• Gives analysts a reference point for tracking further milestones

Why does the vessel matter?

An FPSO acquisition is a capital-intensive step that typically signals a company is advancing a field development toward production rather than remaining in pure exploration mode. For a mid-cap explorer, owning a vessel outright — rather than leasing one under a charter — shifts the cost structure and the execution risk onto the balance sheet.

The OSX-1 was originally built for service offshore Brazil, where it produced from the Waimea field in the Campos basin for OSX Brasil before that company's insolvency proceedings. The vessel has since been held in storage pending redeployment.

What comes next?

The watch items from here are concrete: any follow-on announcements on vessel refurbishment scope, timing for tow and yard works, and the field or fields where Rockhopper intends to deploy the unit. Investors will also look for updated cost guidance and schedule milestones in the company's next results or operational update.

Rockhopper's regulatory filing is the first formal marker in that sequence. Subsequent disclosures will determine whether the acquisition converts into a firm redeployment timeline.

Editor's note: This item is based on the headline and disclosure notice referenced above; readers should consult the full RNS text on Rockhopper's investor relations page for the complete terms of the update.