Singapore Frigate Spotted With Blue Spear Anti-Ship Missiles

"A container for the missile is clearly visible aboard Steadfast," photographer Koji Inoue wrote, sharing images that TWZ published on August 19, 2026.

RSS Steadfast in Tokyo: a first visual confirmation

Photographs shared with TWZ by Koji Inoue (@kojiinet on X) show what appears to be a Blue Spear surface-to-surface missile container mounted aboard RSS Steadfast, the third of six Formidable class frigates. The ship was in port at the Tokyo International Cruise Terminal and is scheduled to open for guided public tours on August 21–22, 2026. In the Tokyo images, a single quad launcher—described in reporting as the minimum fit for the visit—is visible on the missile deck.

Blue Spear (the 5G SSM): reported capabilities

According to specifications released by Proteus Advanced Systems, Blue Spear, also called the 5G SSM, is a turbojet-powered, subsonic surface-to-surface missile with a range of around 180 miles. The weapon is designed for beyond-line-of-sight engagements against both maritime and land targets. Proteus says the missile incorporates a radio-frequency seeker and guidance intended to operate in complex electromagnetic environments and offers fire-and-forget or fire-and-update employment modes. The missile uses "advanced algorithms" for target discrimination, can engage moving targets, dynamically modify its flight path during an engagement, and adopts a low-level, sea-skimming approach to reduce detection and interception chances. Proteus has said it has considered installing an imaging infrared seeker if required.

Formidable class mid-life upgrade: missiles and more

Singapore previously disclosed that Blue Spear will replace the Formidable class’s legacy Harpoon anti-ship missiles as part of a mid-life upgrade (MLU). The MLU will also introduce upgrades to combat management, communications, and engineering systems, according to Singapore’s Ministry of Defense. Each Formidable was capable of carrying as many as 24 Harpoons—via six quad packs on the missile deck—and reporting notes that the likelihood is the same 24-missile capacity will be retained for Blue Spear. For Steadfast’s Japan visit, the ship is fitted with the single quad launcher visible in the images.

Proteus, the Israel–Singapore joint venture, and export prospects

Blue Spear is produced by Proteus Advanced Systems, a joint venture between Israel Aerospace Industries and Singapore’s ST Engineering. The weapon traces its development lineage to the Israeli Gabriel family and was publicly displayed for the first time at the Singapore Airshow 2022 following a contract with the Estonian Defense Forces to meet a coastal anti-ship requirement; in Estonia’s configuration the missile is fired from a truck-based launcher. After sales to Estonia and Singapore, Proteus is marketing Blue Spear to potential buyers across Southeast Asia, Europe, and Latin America. Proteus pitched the missile to the U.K. under the name Sea Serpent for the Interim Surface-to-Surface Guided Weapon (I-SSGW) requirement, but that contest was won by the Kongsberg Naval Strike Missile (NSM).

What this means for the Republic of Singapore Navy, Proteus, and regional navies

• Republic of Singapore Navy: The transition from the Harpoon—which the RSN introduced on Sea Wolf missile gun boats in the late 1980s and continued aboard Victory class corvettes in the 1990s and the Formidable class from 2005 onwards—adds substantially longer-range strike to the Formidable fleet. The move forms part of a broader modernization that also includes new Multi-Role Combat Vessels (MRCV), additional Type 218SG submarines (two more in addition to the previous four), and Boeing P-8A Poseidon aircraft.
• Proteus and suppliers: The installation aboard a high-profile Singapore frigate provides a visible reference point as Proteus seeks further export customers and positions Blue Spear as a Harpoon successor in multiple regions.
• Regional navies: Journalists and contributors cited in reporting note that the move helps Singapore "keep pace with the growing lethality and range of new and upgraded anti-ship missiles" in the region. Roy Choo highlighted neighboring forces that operate or are acquiring long-range ship-launched missiles, citing Indonesian use of the Russian-made Yakhont and forthcoming Turkish-made ATMACA, and Malaysia’s search to replace a previously planned Naval Strike Missile acquisition.

The images of RSS Steadfast thus provide the first publicly available photographic evidence that Blue Spear has been fitted to a Formidable class hull, underscoring how missile replacement is a visible element of Singapore’s broader naval modernization. The ship’s planned public tours in Tokyo on August 21–22, 2026, will give observers a chance to see the installation in person; for Proteus, the fitment aboard Steadfast offers a prominent example to show potential customers. Whether Singapore will fit other Formidable ships with the same minimum quad launcher or move to fuller loadouts that exploit the class’s potential 24-missile capacity remains an immediate operational question tied to the wider mid-life upgrade schedule.

Original reporting: https://www.twz.com/sea/singapores-formidable-class-frigate-appears-armed-with-blue-spear-missiles