THIS ANNOUNCEMENT AND THE INFORMATION CONTAINED HEREIN, IS RESTRICTED AND IS NOT FOR RELEASE, PUBLICATION, DISTRIBUTION OR FORWARDING, IN WHOLE OR IN PART, DIRECTLY OR INDIRECTLY, IN OR INTO THE UNITED STATES, AUSTRALIA, CANADA, JAPAN, THE REPUBLIC OF SOUTH AFRICA OR ANY OTHER JURISDICTION IN WHICH SUCH RELEASE, PUBLICATION OR DISTRIBUTION WOULD BE UNLAWFUL.

THIS ANNOUNCEMENT IS FOR INFORMATION PURPOSES ONLY AND IS NOT AN OFFER OF SECURITIES IN ANY JURISDICTION. PLEASE SEE THE IMPORTANT NOTICES AT THE END OF THIS ANNOUNCEMENT.

THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION FOR IMMEDIATE RELEASE

24 August 2026

Rockhopper Exploration plc

("Rockhopper" or the "Company")

Sea Lion Operator's Update

Intention to Undertake an Equity Capital Raising

Rockhopper Exploration plc (AIM: RKH), the oil and gas company with key interests in the North Falkland Basin ("NFB"), notes the update published this morning by the operator Navitas Petroleum LP ("Navitas LP"), which holds its interests in the NFB through its indirect subsidiary Navitas Petroleum Development and Production Ltd, ("Navitas" or the "Operator") on Sea Lion (the "Project") development progress.

Additional FPSO

As previously disclosed in May this year, Navitas was investigating accelerating the development of subsequent phases of the Sea Lion development beyond phase 1 of the Northern Development Area ("NDA Phase 1"). Accordingly, Navitas (through a subsidiary) signed a Memorandum of Understanding ("MOU") for an additional FPSO. Navitas estimates this could increase Sea Lion production capacity by a further 125,000 bopd (43,750 bopd net to Rockhopper) and accelerate subsequent production phases when compared to current plans.

Navitas has today provided an update that it has (through a subsidiary) exercised an option to acquire the second FPSO, named the OSX-1, and the completion of the acquisition is expected during the coming month. The aggregate cost of acquiring the OSX-1 (excluding the anticipated upgrade costs) is approximately US$125 million. Navitas will initially be the sole owner through an incorporated special purpose vehicle and will bear 100% of the related costs until Rockhopper funds its share. Rockhopper is currently in discussions with Navitas about how the OSX-1 will be formally incorporated into its existing Sea Lion joint venture agreements.

Whilst the development of the NDA Phase 1 remains on track for first oil in Q1 2028, the plan set out by Navitas is for the OSX-1 to be used to develop the resources in the Central Development Area ("CDA") of the Sea Lion field, thereby accelerating production of these barrels. The CDA work programme is expected to include the drilling of 20 wells in CDA Phase 1 and 18 wells in CDA Phase 2, for a total of 38 wells. Navitas intends to submit the CDA Development Plan to the Falkland Islands Government for approval and to make a Final Investment Decision ("FID") in respect thereof in the first half of 2028. Navitas is targeting production from the development of CDA Phase 1 by the end of 2030.

Navitas Updated Independent Reserves and Resource Report

Navitas has today also provided an updated reserves and resources report prepared on its behalf by Netherland, Sewell & Associates Inc (NSAI), which incorporates the accelerated development plan for the CDA following the purchase of the OSX-1 (the "Updated Navitas NSAI Report").

As set out in Navitas's announcement this morning, the Updated Navitas NSAI Report, which uses long term Brent crude oil price of $76/bbl, shows the discounted cash flow attributable to Navitas increase approximately 39% when compared to the previous Navitas NSAI Report dated February 2026.

Rockhopper anticipates publishing a new NSAI report net to its 35% shortly which the Board believes is likely to show a similar proportionate increase in its own post tax NPV10 from the current estimate of US$2.2bn.

The Updated Navitas 2026 NSAI Report will be made available on Navitas' website shortly.

Falklands Exploration

Navitas is considering various options for exploration activity during the upcoming drilling campaign for the NDA Phase 1. This may include an oil exploration well in the licence covering the Sea Lion discovery area and may also include the deepening of a development well to target the Gwendoline exploration prospect.

Progress in Development of the NDA Phase 1 of Sea Lion

Navitas reports other progress on the Sea Lion NDA Phase 1 development as follows:

·      Development works in the Falkland Islands are progressing to plan and, at this stage, are focused on: (i) preparing the quay and the shore base that will serve the Project; (ii) constructing accommodation; and (iii) carrying out additional infrastructure works in preparation for the arrival of the drilling rig in the Falklands and commencement of drilling in early 2027.

•    The manufacture of the long-lead items including flexible flowlines, wellheads, and subsea Xmas trees is continuing. 

•    The Aoka Mizu FPSO has been disconnected from the field it previously served and is on route to a shipyard in Southeast Asia, with its arrival expected in early September 2026.

Rockhopper's Intention to Undertake an Equity Capital Raising

The purchase of the OSX-1, as noted above, will be undertaken by an SPV 100% owned by Navitas LP. Navitas and Rockhopper are discussing the optimal arrangement for how the acquisition of the FPSO might be structured between the parties. However, while these talks are ongoing, it is clear Rockhopper requires funding to be in place in order to take-up its pro rata ownership of the vessel (35%) and meet any associated pre-FID costs.

The Company has received strong indications of interest from existing shareholders and potential new investors to support the Company in the acquisition of its pro rata share of the OSX-1 and to fully participate in the consequential accelerated development of the CDA. Accordingly, the Company is actively considering a placing of new ordinary shares to new and existing investors (the "Placing").

Following the updates to the AIM Rules for Companies announced earlier this month, the Company has decided to utilise a Capital Access Window. This is a voluntary pause to the trading of a company's shares to make it easier for companies to reach a broader range of investors during a fundraise. From 7:45 a.m. BST today, the Company's shares will enter a Capital Access Window until a further announcement is made detailing the results of the Placing.

In addition to the Placing, the Company is actively considering an open offer to all existing shareholders (the "Open Offer" and, together with the Placing, the "Capital Raising"), providing them with the opportunity to invest in the Company on the same economic terms as those investing in the Placing.

This announcement does not constitute an offer of securities in any jurisdiction. The Capital Raising, if implemented, will be the subject of further announcements, including the full terms and conditions of the Placing and Open Offer, respectively. Further announcements will be made as and when appropriate.

Samuel Moody, Chief Executive Officer of Rockhopper, commented:

"Today's update from Navitas reflects its continued commitment to developing and accelerating Sea Lion, and the consequential significant enhancement of the Project's value. We are working alongside Navitas to ascertain the optimal structure for Sea Lion's participation in OSX-1 and are planning a Capital Raising to secure the required financing. We have already received positive indications of support for this financing and we look forward to updating the market in due course as appropriate." 

Enquiries:

Rockhopper Exploration plc

Sam Moody - Chief Executive Officer

Tel. +44 (0)20 7390 0230 (via Vigo Consulting)

Canaccord Genuity Limited (NOMAD and Joint Broker)

Henry Fitzgerald-O'Connor / James Asensio / Charlie Hammond

Tel. +44 (0)20 7523 8000

Peel Hunt LLP (Joint Broker)

Richard Crichton / Georgia Langoulant

Tel. +44 (0)20 7418 8900

Vigo Consulting

Patrick d'Ancona / Ben Simons / Fiona Hetherington

Tel. +44 (0)20 7390 0234

Notes to Editors

Rockhopper Exploration plc is a UK-based oil and gas exploration and production company with key interests in the Falkland Islands. The Company holds a 35 per cent interest in licences in the North Falkland Basin, where it has sanctioned the development of the significant Sea Lion field, originally discovered by the Company in 2010.

Rockhopper's shares are quoted on the AIM market of the London Stock Exchange under the ticker RKH.

For more information, visit the Company's website at www.rockhopperexploration.co.uk.

IMPORTANT INFORMATION

The information contained within this announcement is deemed by the Company to constitute inside information as stipulated under Article 7 of the Market Abuse Regulation (EU) No. 596/2014 (as amended) as it forms part of the domestic law of the United Kingdom by virtue of the European Union (Withdrawal) Act 2018 (as amended). Upon the publication of this announcement via the Regulatory Information Service, this inside information is now considered to be in the public domain.

This Announcement contains (or may contain) certain forward-looking statements with respect to certain of the Company's plans and its current goals and expectations relating to its future financial condition and performance and which involve a number of risks and uncertainties. The Company cautions readers that no forward-looking statement is a guarantee of future performance and that actual results could differ materially from those contained in the forward-looking statements. These forward-looking statements can be identified by the fact that they do not relate only to historical or current facts. Forward-looking statements sometimes use words such as "aim", "anticipate", "target", "expect", "estimate", "intend", "plan", "goal", "believe", or other words of similar meaning. By their nature, forward-looking statements involve risk and uncertainty because they relate to future events and circumstances, including, but not limited to, economic and business conditions, the effects of continued volatility in credit markets, market-related risks such as changes in the price of commodities or changes in interest rates and foreign exchange rates, the policies and actions of governmental and regulatory authorities, changes in legislation, the further development of standards and interpretations under International Financial Reporting Standards ("IFRS") applicable to past, current and future periods, evolving practices with regard to the interpretation and application of standards under IFRS, the outcome of pending and future litigation or regulatory investigations, the success of future explorations, acquisitions and other strategic transactions and the impact of competition. A number of these factors are beyond the Company's control. As a result, the Company's actual future results may differ materially from the plans, goals, and expectations set forth in the Company's forward-looking statements. You should not place undue reliance on forward-looking statements. Any forward-looking statements made in this Announcement by or on behalf of the Company speak only as of the date they are made. Except as required by the FCA, the London Stock Exchange or applicable law, the Company expressly disclaims any obligation or undertaking to release publicly any updates or revisions to any forward-looking statements contained in this Announcement to reflect any changes in the Company's expectations with regard thereto or any changes in events, conditions or circumstances on which any such statement is based.

This Announcement is for information purposes only and shall not constitute an offer to buy, sell, issue, or subscribe for, or the solicitation of an offer to buy, sell, issue, or subscribe for any securities, nor shall there be any offer, solicitation or sale of securities in any jurisdiction in which such offer, solicitation or sale would be unauthorised or unlawful prior to registration or qualification under the securities laws of any such jurisdiction. Any failure to comply with these restrictions may constitute a violation of the securities law of any such jurisdiction.

This Announcement is not an offer of securities for sale in or into the United States. Any new ordinary shares issued pursuant to the Capital Raising (the "New Ordinary Shares") have not been and will not be registered under the US Securities Act 1933, as amended (the "Securities Act") or with any securities regulatory authority of any state or other jurisdiction of the United States and may not be offered, sold, delivered, transferred, or taken up, directly or indirectly, in or into the United States except pursuant to an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act and in compliance with any applicable securities laws of any state or other jurisdiction of the United States. There will be no offer of the New Ordinary Shares in the United States.

This document does not constitute a prospectus under the Israeli Securities Law, 5728-1968 (the "Israeli Securities Law"), and has not been filed with or approved by the Israel Securities Authority. In Israel, this document is being distributed only to, and is directed only at, and any offer of the Placing Shares is directed only at: (i) a limited number of persons in accordance with the Israeli Securities Law, and (ii) investors listed in the first addendum (the "Addendum") to the Israeli Securities Law, consisting primarily of joint investment in trust funds, provident funds, insurance companies, banks, portfolio managers, investment advisors, members of the Tel Aviv Stock Exchange, underwriters, venture capital funds, entities with equity in excess of NIS 50 million and 'qualified individuals', each as defined in the Addendum (as it may be amended from time to time), collectively referred to as qualified investors (in each case, purchasing for their own account or, where permitted under the Addendum, for the accounts of their clients who are investors listed in the Addendum). Qualified investors are required to submit written confirmation that they fall within the scope of the Addendum, are aware of the meaning of same and agree to it.

This Announcement does not contain an offer or constitute any part of an offer to the public. This Announcement is not a "prospectus" within the meaning of Regulation 21(1) of the Public Offers and Admissions to Trading Regulations 2024 ("POATR") and a copy of it has not been, and will not be, delivered to any authority which could be a competent authority for the purpose of the Prospectus Regulation (EU) 2017/1129 (the "EU Prospectus Regulation").

This Announcement has been issued by and is the sole responsibility of the Company. No representation or warranty, express or implied, is or will be made as to, or in relation to, and no responsibility or liability is or will be accepted by the Joint Brokers (apart from the responsibilities or liabilities that may be imposed by the FSMA or other regulatory regime established thereunder) or by any of their respective affiliates or agents as to, or in relation to, the accuracy or completeness of this Announcement or any other written or oral information made available to or publicly available to any interested party or its advisers, and any liability therefor is expressly disclaimed.

The distribution of this Announcement and the offering of the New Ordinary Shares in certain jurisdictions may be restricted by law. No action has been taken by the Company, Canaccord or Peel Hunt that would permit an offering of such securities or possession or distribution of this Announcement or any other offering or publicity material relating to such securities in any jurisdiction where action for that purpose is required. Persons into whose possession this Announcement comes are required to inform themselves about, and to observe, such restrictions.

The contents of this Announcement are not to be construed as financial, legal, business or tax advice. If you do not understand the contents of this Announcement you should consult an authorised financial adviser, legal adviser, business adviser or tax adviser for financial, legal, business or tax advice.

The information in this Announcement may not be forwarded or distributed to any other person and may not be reproduced in any manner whatsoever. Any forwarding, distribution, dissemination, reproduction, or disclosure of this information in whole or in part is unauthorised. Failure to comply with this directive may result in a violation of the Securities Act or the applicable laws of other jurisdictions.

Neither the content of the Company's website nor any website accessible by hyperlinks on the Company's website is incorporated in, or forms part of, this Announcement.