June 16, 2026

Gulf Marine Services PLC

('Gulf Marine Services', 'GMS', 'the Company' or 'the Group')

Update on the situation in the GCC

Gulf Marine Services ("GMS" or the "Company"), a leading provider of self-propelled, self-elevating support vessels ("SESVs") to the offshore energy industry, is pleased to confirm that all vessels temporarily evacuated from one of the countries in the Gulf due to the prevailing geopolitical situation have now successfully returned to hire on the same contracts.

The Company is maintaining its adjusted EBITDA guidance for 2026 in the range of USD 105 million to USD 115 million but continues to assess the final financial impact of this disruption through ongoing discussions with its clients. A further update will be provided in due course.

Mansour Al Alami, Executive Chairman of GMS, commented:

"We are very pleased to confirm that the fourth and final evacuated vessel has now returned to hire. This is a significant milestone, and we are encouraged by the positive momentum we are seeing both operationally and on the geopolitical front. The swift and safe return of all four vessels is a testament to the professionalism of our crews and the strength of our client relationships, which have remained robust throughout this period.

Looking ahead, we remain confident in the underlying performance of the business and are maintaining our adjusted EBITDA guidance for 2026 in the range of USD 105 million to USD 115 million. We believe GMS is well-positioned to capitalise on the strong demand environment across the Gulf, and we look forward to updating the market further in due course."

This announcement contains inside information and is provided in accordance with the requirements of Article 17 of the Market Abuse Regulation (EU) No. 596/2014 (as it forms part of UK law by virtue of the European Union (Withdrawal) Act 2018, as amended).

-ENDS-

Notes to Editors:

Gulf Marine Services PLC, a company listed on the London Stock Exchange, was founded in Abu Dhabi in 1977 and has become a world-leading provider of advanced self-propelled self-elevating support vessels (SESVs). The fleet serves the offshore energy industries from its offices in the United Arab Emirates, Saudi Arabia, and Qatar. The Group's assets are capable of serving clients' requirements across the globe, including those in the Middle East, South East Asia, West Africa, North America, the Gulf of Mexico, and Europe.

The GMS fleet of 15 SESVs is amongst the youngest in the industry. The vessels support GMS's clients in a broad range of offshore platform refurbishment and maintenance activities, well intervention work, and offshore wind turbine maintenance work (which are opex-led activities), as well as offshore platform installation and decommissioning and offshore wind turbine installation (which are capex-led activities).

The SESVs are categorised by size - K-Class (Small), S-Class (Mid), and E-Class (Large) - with these capable of operating in water depths of 45m to 80m depending on leg length. The vessels are four-legged and are self-propelled, which means they do not require tugs or similar support vessels for moves between locations in the field; this makes them significantly more cost-effective and time-efficient than conventional offshore support vessels without self-propulsion. They have a large deck space, crane capacity, and accommodation facilities (for up to 300 people) that can be adapted to the requirements of the Group's clients.

Gulf Marine Services PLC's Legal Entity Identifier is 213800IGS2QE89SAJF77

www.gmsplc.com

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Cautionary Statement

This announcement includes statements that are forward-looking in nature. All statements other than statements of historical fact are capable of interpretation as forward-looking statements. These statements may generally, but not always, be identified by the use of words such as 'will', 'should', 'could', 'estimate', 'goals', 'outlook', 'probably', 'project', 'risks', 'schedule', 'seek', 'target', 'expects', 'is expected to', 'aims', 'may', 'objective', 'is likely to', 'intends', 'believes', 'anticipates', 'plans', 'we see' or similar expressions. By their nature these forward-looking statements involve numerous assumptions, risks and uncertainties, both general and specific, as they relate to events and depend on circumstances that might occur in the future.

Accordingly, the actual results, operations, performance or achievements of the Company and its subsidiaries may be materially different from any future results, operations, performance or achievements expressed or implied by such forward-looking statements, due to known and unknown risks, uncertainties and other factors. Neither Gulf Marine Services PLC nor any of its subsidiaries undertake any obligation to publicly update or revise any forward-looking statement as a result of new information, future events or other information. No part of this announcement constitutes, or shall be taken to constitute, an invitation or inducement to invest the Company or any other entity and must not be relied upon in any way in connection with any investment decision. All written and oral forward-looking statements attributable to the Company or to persons acting on the Company's behalf are expressly qualified in their entirety by the cautionary statements referred to above.