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Spanish Maritime Forces

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In today's rapidly changing global security landscape, the maritime domain is vital to the prosperity of NATO and its member nations. The domain connects allies through global shipping routes and critical infrastructure, such as underwater communication cables and energy supply lines, facilitating secure trade, reliable communication and economic stability. 

Modern conflicts have shown that response times are critically limited in a crisis. This makes it important to maintain highly mobile, flexible forces that can deploy rapidly. The maritime domain gives NATO a strategic advantage, allowing the Alliance to project power, protect vital sea lines of communication and respond swiftly to emerging threats. The maritime domain is essential to the effectiveness of NATO's Allied Reaction Force (ARF). 

Protecting these shared sea-based networks ensures the uninterrupted flow of goods, information and resources, which are essential for collective security and growth. That is why the Alliance maintains a robust maritime presence 24/7, 365 days a year. With the commitment and contribution of the 27 navies of its 32 member nations, NATO demonstrates unwavering dedication to safeguarding its interests at sea.

Furthermore, the lessons learned from current global conflicts emphasise the need to react to crises at short notice while maintaining flexibility to respond to a wide range of threats. To meet this challenge, NATO’s ARF has a Maritime Component Command (MCC) capable of ensuring a robust command and control structure that can produce effects both at sea and from the sea. 

SPMARFOR: Evolution and Structure

The Spanish Maritime Forces HQ (SPMARFOR) was established shortly before the creation of the NATO Response Force in November 2002. Originally part of the Maritime High Readiness Forces (HRF-M), Spain was one of the four original nations – alongside France, Italy and the United Kingdom – to offer the Alliance a deployable maritime headquarters as part of the NATO Response Force (NRF).

Located in Rota Naval Base, SPMARFOR comprises a permanent staff of 85 dedicated personnel, operating from its command ship, the ESPS Castilla. This deployable and permanently available command structure can adopt various national and international roles, mainly as an MCC or Combined Task Force (CTF). In order to meet any challenges it may have to face as part of a crisis or conflict, the number of staff can be increased up to a maximum of 180 people (called “augmentees”).

The HQ is capable of conducting maritime, amphibious, air, expeditionary and strike operations. All of these roles ensure that SPMARFOR has the ability to project naval power and create effects at sea and from the sea.

SPMARFOR has successfully completed the certification process multiple times in the past, the last time being in 2019, which allowed this HQ to serve as NATO’s NRF MCC in 2020. 

Since then, SPMARFOR has expanded into a larger structure, designed to meet the growing demands of joint operations and new capabilities. This ensures it can effectively serve as NATO’s ARF MCC or CTF for the various Regional Plans under the Deterrence and Defence of the Euro-Atlantic Area (DDA) Concept in the coming years.

Path to Certification

SPMARFOR's path to certification as one of NATO’s ARF MCCs started in the summer of 2023. As part of its preparations for its ARF stand-by period starting on 1 July 2025, over a two-year period, SPMARFOR will have been involved in three major exercises: Steadfast Dagger 24, Dynamic Mariner 25 and Steadfast Cobalt 25. These exercises have enabled SPMARFOR to demonstrate its capability to lead NATO's maritime forces and contribute to the Alliance's collective defence and crisis response if needed.

During certification, the Maritime Allied Command (MARCOM) oversees a rigorous evaluation process that includes deploying a specialised maritime evaluation team to assess operational capabilities on board the command ship. SPMARFOR's ability to plan and execute complex maritime operations, coordinate multinational forces and respond to various crisis scenarios has been thoroughly tested. Following the successful evaluation during Dynamic Mariner/Flotex-25, SPMARFOR has achieved the status of “MISSION CAPABLE WITHOUT LIMITATIONS,” as certified by MARCOM.

DYNAMIC MARINER/FLOTEX-25

DYNAMIC MARINER/FLOTEX-25

The Alliance's maritime forces conduct over 20 naval exercises annually, ensuring constant readiness and adaptability in an increasingly complex operational environment. Among these exercises, Dynamic Mariner/Flotex-25 stood out in 2025 as NATO’s most ambitious and significant exercise.

It was conducted from 24 March to 4 April in the Gulf of Cadiz and Alboran Sea. It was one of the biggest exercises in recent years both for NATO and Spain. It brought together:

• Over 5,000 military personnel from eight Allied nations: Spain, Türkiye, Portugal, Italy, France, Greece, Germany and the United States.
• 25 surface vessels, including NATO's Standing Naval Groups and 2 submarines.

• Maritime Patrol Aircraft (including US P-8A Poseidon, Portuguese P-3C Orion, and French Atlantique 2) and helicopters from various nations.
• Advanced autonomous systems including Predator and Scan Eagle UAVs from Spain and various USVs from Supreme Allied Command Transformation (SACT).
• Specialised electronic warfare assets from NATO's Joint Electronic Warfare Core Staff, which is permanently based in Yeovilton in the United Kingdom.

Dynamic Mariner/Flotex-25 was an opportunity for NATO to train the ability of maritime forces to project naval power and exercise sea control in a fictional scenario, inspired by the Gulf of Guinea, with medium- and high-intensity operations. This made it possible to replicate a crisis that requires the deployment of naval forces far from allied shores. 

Participants were able to test their capabilities in naval power projection, command and control, amphibious operations, anti-submarine warfare and cyber defence, among others, integrating the most advanced technologies and incorporating unmanned systems (UXV).

Multi-Domain Operations

Dynamic Mariner/Flotex-25 showcased SPMARFOR's mastery of modern warfare capabilities, demonstrating the HQ’s ability to create effects across the whole spectrum of multi-domain operations. The key elements were:

• Integration of autonomous surface and aerial vehicles, both in defensive and offensive roles.
• Advanced cyber defence operations, including cyber incidents (defacement, phishing, DDoS, etc.) coordinated through Spain’s Joint Cyberspace Command.
• Full integration of Information Operations into the Targeting Cycle. This included CIMIC activities, Simulated Press (SIMPRESS) interaction, managing merchant traffic through the NCAGS/AWNIS cell, coordination with Spanish Space Command, etc. 
• Electronic warfare exercises involving the Spanish Army’s EW Regiment and NATO’s JEWCS assets. This made it possible to train in a congested electromagnetic environment including radar, GPS and communications jamming.

In short, SPMARFOR was able to exercise multi-domain operations spanning the maritime, air, cyber and space domains, with contributions from the Spanish Army, Air and Space Force, and National Institute of Aerospace Technology.

All ahead full into the future

Following its successful evaluation, SPMARFOR has officially assumed, as of 1 July 2025, its stand-by role as NATO’s Maritime Component Command for the Alliance Response Force (ARF). Ready to respond to any maritime security challenge faced by the Alliance, this milestone marks the beginning of a series of significant yearly commitments. SPMARFOR is now set to take on the role of Combined Task Force (CTF) Atlantic under JFC Norfolk in July 2026, followed by the role of CTF Mediterranean under JFC Naples in July 2027.

These appointments highlight SPMARFOR’s vital role in maintaining NATO’s maritime security and its readiness to adapt to shifting security challenges in an increasingly complex environment.