SINGAPORE: Not every threat at sea calls for a warship. Many maritime security challenges today require more than routine law enforcement but less than a conventional military response.

It is in this space that Singapore’s new offshore patrol vessels (OPVs) are intended to operate. On Friday (Oct 2), the Republic of Singapore Navy (RSN) launched the first of its four OPVs which will join the Maritime Security and Response Flotilla to “enable more calibrated responses”.

The OPVs, acquired from Germany’s Fassmer, will be delivered to the navy progressively from 2028 to replace the existing, smaller Sentinel-class maritime security and response vessels (MSRVs).

Two peculiar features stand out of this new class of OPVs: The vessels do not sport the usual grey livery of navy vessels; instead, they are painted white. They will also not use the RSS (Republic of Singapore Ship) prefix usually assigned to commissioned vessels. These suggest that Singapore does not intend for the OPVs to be operated like regular Navy warships.

THE NEED FOR MORE OPTIONS AT SEA The challenge comes as threats at sea become more complex. Incidents, such as maritime coercion and threats to critical underwater infrastructure, can have strategic consequences yet fall short of an armed attack and may not necessarily require a militarised response.

This is especially when incidents involve civilian or commercial vessels. For example in October 2023, a Baltic Sea gas pipeline and subsea telecommunications cables between Finland and Estonia were severed. A container ship, the NewNew Polar Bear, allegedly dragged its anchor across the seafloor. Even then, the distinction between an accident and intentional sabotage is hard to prove.

This is where optics also matter as part of the message. A heavily-armed “grey hull” warship facing down a civilian vessel – lightly armed or even unarmed – would be overkill and could send a signal of escalation if the countries involved face existing maritime tensions.

This helps explain why there has been a “white hull” proliferation across Asia, referring to vessels typically associated with coastguards and maritime law enforcement.

Despite its rapid navy buildup, China has continued to pour immense resources into bulking up its coastguard, which spearheads its maritime sovereignty and rights assertion in contentious waters such as the South China Sea. The Philippines has likewise been expanding and modernising its coastguard.

In theory, white hulls could project a less militaristic impression, especially when deployed to politically sensitive areas.

In practice however, this “grey versus white” distinction has become blurred. Navies perform important peacetime roles. Some coastguards undertake roles traditionally associated with navies and are part of the defence establishments such as in India and Vietnam, or are integral parts of navies, such as in Norway and Colombia.

WHAT MORE CALIBRATED MEANS What makes Singapore’s new OPVs an interesting addition to the fleet is the combination of the force they can bring to bear, where they can operate and the signal their deployment sends.

During his speech at the Committee of Supply Debate in February 2026, Singapore Defence Minister Chan Chun Sing said that the Singapore Armed Forces (SAF) must possess not just “robust conventional capabilities” but also “other calibrated options in response to an expanded range of scenarios beyond and below the threshold of war”.

The OPVs are equipped with both lethal and non-lethal capabilities and make available a broader set of capabilities to the fleet, such as unmanned systems, that the RSN can flexibly employ across a spectrum of low to high-intensity missions.

The OPVs are substantially larger than the vessels they will replace: They measure about 95 metres-long and displace close to 2700 tonnes, compared to the current MSRVs at 55m and 500 tonnes. This gives them longer operating range, at-sea endurance and space to flexibly accommodate a variety of payload modules depending on the mission.

This also helps explain why the OPVs sit within the RSN rather than the Police Coast Guard (PCG), whose mandate is confined to Singapore’s territorial waters. The RSN can operate beyond that – which allows for flexibility to address threats farther afield or for maritime security cooperation activities with regional partners.

Like many regional countries seeking to promote stability at sea, Singapore’s new OPVs reflect this continued emphasis on projecting a less militaristic impression: a platform that is operated by the navy yet operating under the threshold of armed conflict. Taken together, these features give more room for calibration.

DOING MORE WITH A SMALL NAVY Many navies worldwide, especially small ones like the RSN face a practical challenge: An increasingly complex maritime security environment requires us to do more with finite resources.

The perennial issue of manpower concerns has long dogged the SAF, which puts emphasis on multi-role platforms that require less crew yet flexible enough to adapt to different mission requirements. The OPVs fit that logic. Singapore’s approach is instructive in how small navies seek to draw a tight balance between an expanding mission scope and capacity constraints in the context of evolving maritime security challenges.

Collin Koh is Senior Fellow at the Institute of Defence & Strategic Studies, a constituent of the S Rajaratnam School of International Studies, based at Nanyang Technological University, Singapore.