India-Pakistan 1991 Naval Agreement: Article 10 and Maritime CBMs Explained

Overview

The 1991 bilateral Agreement on Advance Notice on Military Exercises between India and Pakistan establishes mandatory protocols to prevent naval collisions. Its core provision, Article 10, prohibits warships and submarines of both navies from approaching within three nautical miles of each other in international waters.

This framework serves as a foundational instrument of crisis de-escalation in the congested waters of the Arabian Sea. However, recurrent tactical close encounters, communication deficits, and unresolved maritime boundaries test its enforcement. Upgrading these measures with direct bridge-to-bridge communication links remains essential for regional maritime stability.

Bilateral naval safety protocols drew fresh diplomatic scrutiny following an incident in the North Arabian Sea:

• September 2026 Incident: As reported by the Ministry of External Affairs in September 2026, Pakistan Naval Ship PNS Hunain made high-speed, unsafe contact with an Indian Navy frontline warship operating on routine surveillance approximately 120 nautical miles east of Oman.
• Diplomatic Demarche: India's Ministry of External Affairs summoned Pakistan's Charge d'Affaires Saad Ahmad Warraich in New Delhi on 16 September 2026 to lodge a formal diplomatic protest against the breach of bilateral obligations.
• June 2011 Precedent: Pakistan Navy frigate PNS Babur brushed against Indian Navy frigate INS Godavari in the Gulf of Aden, damaging the Indian vessel's helicopter safety net.

These recurring encounters highlight the operational vulnerability of bilateral agreements during routine naval patrols.

The Government of India and the Government of Pakistan signed the Agreement on Advance Notice on Military Exercises, Manoeuvres and Troop Movements on 6 April 1991.

Diplomatic representatives formulated the pact alongside airspace safety measures to build institutional transparency. The treaty officially entered into force on 19 August 1992, creating a legal framework for prior notifications of major troop movements across land, airspace, and maritime boundaries.

The post-Cold War security environment in South Asia demanded predictable rules for military manoeuvres. By instituting mandatory notification thresholds, both nations sought to prevent routine training exercises from being misread as offensive preparations.

Article 10 of the 1991 Agreement establishes the primary operational safety buffer governing naval vessels and submarines of India and Pakistan in international waters.

The clause mandates that naval ships and submarines of both countries shall not close within three nautical miles of each other while navigating international waters. This buffer eliminates collision hazards and curtails aggressive tactical posturing.

The rule provides an unambiguous benchmark for bridge officers navigating crowded shipping corridors. Maintaining this fixed distance preserves adequate reaction time if a vessel encounters mechanical failure or navigational drift.

The 1991 Agreement outlines specific operational thresholds to prevent strategic surprises between the two navies.

Advance notification is mandatory when an exercise involves six or more ships of destroyer or frigate size operating in company and crossing into the other country's Exclusive Economic Zone. This protocol prevents large fleet deployments from triggering retaliatory defensive alerts.

Communication between the two defence establishments relies primarily on established military channels. The Director General of Military Operations (DGMO) hotline serves as the primary conduit for high-level clarifications during unexpected operational encounters.

Structural deficits within existing India-Pakistan maritime agreements undermine operational compliance and elevate escalation risks during unplanned encounters.

According to the Institute for Defence Studies and Analyses (IDSA), the 1991 framework lacks automated technical verification mechanisms, institutionalised bridge-to-bridge tactical communication links, and binding dispute-resolution provisions. When frontline warships meet unexpectedly, bridge teams lack a shared radio frequency to clarify navigational intent in real time.

1. Tactical Encounter at Sea: Warships encounter one another during high-seas surveillance.
2. Absence of Direct Tactical Hotline: Bridge officers lack dedicated radio links to exchange intentions.
3. Manoeuvre Ambiguity: Navigational movements risk misinterpretation as hostile posturing.
4. High-Risk Close Pass: Uncoordinated steering creates collision hazards and diplomatic escalation.

Under Clause 5 of the Lahore Memorandum of Understanding signed on 21 February 1999, both states agreed to conclude a dedicated bilateral Agreement on Prevention of Incidents at Sea. However, bilateral progress stalled following subsequent geopolitical developments, leaving tactical naval interactions reliant on the outdated 1991 mechanisms.

The unresolved Sir Creek dispute remains a primary maritime flashpoint shaping naval interactions and border enforcement between India and Pakistan:

• Sir Creek Boundary: The dispute centres on a 96-kilometre tidal estuary in the Rann of Kutch dividing Gujarat from Pakistan's Sindh province.
• Overlapping Maritime Zones: Because the land boundary terminus in the creek remains contested, the delimitation of the maritime boundary and the Exclusive Economic Zone extends into conflicting claims across the North Arabian Sea.
• Fishermen Apprehensions: The absence of a settled maritime frontier leads to frequent apprehensions of civilian fishermen by the Indian Coast Guard and the Pakistan Maritime Security Agency near the International Maritime Boundary Line.
• Coast Guard Hotline: To mitigate low-level enforcement friction, the Indian Coast Guard and the Pakistan Maritime Security Agency operationalised a dedicated communication hotline in November 2006 following an agreement signed in October 2005.

Modernising maritime safety frameworks requires establishing institutionalised tactical communication channels and adopting updated multilateral operating codes.

• Finalising an INCSEA Pact: Both nations should implement the pending commitment under the 1999 Lahore Memorandum of Understanding to establish precise rules of engagement for naval combatants.
• Adopting CUES Protocols: Maritime security experts recommend incorporating the Code for Unplanned Encounters at Sea (CUES) standards into bilateral naval standard operating procedures.
• Establishing Tactical Navy-to-Navy Links: A direct communication channel between naval operation directorates would prevent operational ambiguities from escalating into diplomatic confrontations.
• Separating Humanitarian Maritime Issues: Establishing coordinated patrol mechanisms near the Sir Creek estuary can reduce civilian fishermen detentions while formal boundary negotiations remain pending.

• Core Treaty Obligation: The 1991 Agreement on Advance Notice on Military Exercises mandates advance notice for large-scale manoeuvres and establishes operational safety norms between India and Pakistan.
• Article 10 Separation Rule: Article 10 explicitly prohibits Indian and Pakistani naval combatants and submarines from closing within three nautical miles in international waters.
• Operational Deficits: The existing maritime framework lacks direct bridge-to-bridge tactical hotlines and formal verification mechanisms, heightening the risk of naval miscalculations.
• Unresolved Boundary Friction: The unresolved 96-kilometre Sir Creek dispute continues to complicate maritime boundary delimitation and generates recurring enforcement challenges across the Arabian Sea.