• Note: Plz click on the image for better quality

Number	Class Name	IBM/OBM (No. of Engines)	Image	Craft Names  (discovered so far)	Total built	Notes
Very Slender Vessel
1	(class name lost in time)	OBM (2)	Night view: Day light view:	(craft name lost in time)	1	- Used up in the Operation Unceasing Waves-1. Image taken during the operation: 'Thermal imaging by SLAF aircraft during the battle' - Production was stopped for unknown reasons

Edited September 30Sep 30 by நன்னிச் சோழன்

• Note: Plz click on the image for better quality

Number	Class Name	Sub class	IBM/OBM (No. of Engines)	Image	Craft Names  (discovered so far)	Total built	Notes
Boats
1	Mirage	-	OBM (2)		(craft name lost in time)	2	- Specially designed, different-shaped Mirage class bomb-laden crafts for offshore attacks.
2	Kfir  (Also known as Kipir and Kavir colloquially) Nick Name: Idiyan	Stealth 16'	OBM (1)	View from the front of a Kfir-class boat used in a parade (all the items relating to explosives are removed, including the ramming horn): 'During a Maaveerar Naal parade at Mullaitivu sea' View from the front and rear of the stealth boat during a practice session (absence of artillery shells can be seen) Sea Black Tiger Lt. Col. Anpu is seen situated on the boat	Thanikai	10+	- These are stealth crafts used as primary bomb-laden crafts since 1998. - During the Sea Black Tiger attacks, manned by 2 persons. - They are also used for special raid missions (to withdraw landed troops and to conduct commando attacks from sea to ground), wherever required.  - The first boat of this class was used at 1.30 am on March 11, 1998, to sink a Sri Lankan Navy Waterjet-class vessel near Sober Island, Trincomalee. The mission was carried out by Sea Black Tigers Captain Kopi (Aarvalan) and Captain Isaiyalan, who were previously naval commandos belonging to the Sea Leopards Team.
		Stealth 16'	OBM (1)	Two views of the same vessel: 'Double-strapped clamore mine and a single artillery shell on each side can be seen in this image clearly.'	(craft name lost in time)	1+	- These are stealth crafts. - During the Sea Black Tiger attacks, manned by a single person. - Production began in the 4th Eelam War
3	(class name lost in time)	-	OBM (2)		Mathan, Varathan	6+	- Used as bomb-laden crafts from the 2nd Eelam War onwards.
		-	OBM (5)	Bow: Stearn:	(craft name lost in time/ Unnamed)	1	- Specially designed large bomb-laden craft intended to ram into a ship or structures in the Colombo Port. But it was captured after the attack failed
4	(class name lost in time)	-	IBM (2)	1) 2) Image dates to 1998 | Screenshot from Tigers' video documentary named "Uyirayutham"	Amuthan	2
5	Not named	-	OBM (2)	Without the steerer cabin cover:	(craft name lost in time)	1	- A boat with 2 ram points.  - 3 men can travel in it.  - Sometimes the steerman area is covered with a room-like structure. - Camouflaged with unusual colours (blue, green, yellow, white and red) - Production was stopped for unknown reasons

 

• Kfir class boats:

This is based on first-hand accounts written by those directly involved in the production of the stealth boats. For further reference: Stealth type boats of the Sea Tigers

Analysis of the Stealth technology:

The Sea Tigers have said that their design was inspired by an English magazine that featured a stealth aircraft and the building tech in it. They shaped the boat with a pointed bow and a tunnel-hull stern, while the gunwale angles were modelled after the aircraft’s structure. To test how these angles would deflect light, they built a cardboard model and used a torch to simulate radiation before moving on to the actual construction. The above article also states that,

The major feature that is taken into account while constricting a stealth boat is the right angle, which is designed in such a way that it deflects and reflects the radar, and the infrared rays that hit this reflecting surface are known as the radar cross-section. By not constricting the boat with any right angles, such deflection and emerging are avoided, making the vessel a stealth boat.

Distinctive low and wide wing-like structure designed to help lift the heavy bow section out of the water during high speed; the upper surface is angular with a ridge along the bow, lending to an open-topped cockpit.

Flat facets and carefully chosen angles are important aspects in radar tech. They scatter incoming radar energy away from the transmitter instead of reflecting it back — that does reduce RCS for those aspects. The article’s emphasis on right angles and angled surfaces is directly about this.

But the boat's Engines, outboards, propellers, and crews are high-RCS items; even if the hull is faceted, the exposed metal engine and fittings create large radar returns which give out the position of the boat.

RCS depends heavily on the aspect (angle between the radar and the target). Faceting can make a craft almost “invisible” from some angles but still bright from others.

The ones used for special operations have gun mounts on them. But the RADAR return from it is very low. A straight, thin metallic rail is a minor scatterer, especially if it’s aligned along the vessel’s length (specular reflections go away from most radars). It won’t significantly increase the boat’s RCS. The visual of the gun mount is also minimal. Unless the observer is very close or the sun/light catches it just right, it mostly blends into the deck. As there is no barrel or turret, it means no silhouette changes. These gun mounts are removed if they were assigned for bomb-laden attacks.

Its Tri-V hull had a low, wide, wing-like form with an angular ridge and open cockpit, built for stability and speed. The stealth boat’s super-stable hull design enabled it to cruise at 45–50 knots and reach a top speed of 50–55 knots (Acc. to the article).

Thus its evident that they used shape (faceting) + low profile + non-metal construction to reduce RCS and visual profile. That combination — rather than some single miracle of radar-absorbent technology — is what likely made them hard to detect in practice. They were low-observability craft, not full modern stealth vessels, acc. modern stealth standards.

When mission-ready, stealth boats were loaded with up to 200 kg of explosives and fitted with single or double Claymore mines on each side for greater lethality. A 130 mm artillery shell was also attached to each side of the bow. In addition, a ramming horn was fixed to the bow hull. To the tip of the bow, 5-6 triggering switches were attached using a metal structure, which will trigger the explosives once they ram into the target. These were removed during public parades for civilian safety.

In naval/academic language, “stealth” means a craft deliberately designed to reduce its signature (radar, visual, infrared, acoustic). By that definition, the LTTE’s “Kfir-class” do qualify because:

• Their hull was faceted to scatter radar energy,

• They used fiberglass/wood (lower radar reflectivity),

• They had very low freeboard (harder to spot on radar and visually),

• They blended with sea clutter at speed.

In a strict military-technology sense (like US Navy Sea Shadow or Sweden’s Visby-class corvette), these LTTE boats were not full “stealth” platforms:

• Their engines, metal fittings on the bow, weapons (like the artillery shell), and heat signature were not masked and were visibly seen

• Some wires that go along the gunwale and the sides of the boat are visible. To RADARs, thin wires are small compared with many radar wavelengths and often scatter only weakly, but at some frequencies and aspect angles they can act like small reflectors or create resonances that raise the vessel’s radar signature. A few strategically placed protrusions can produce bright returns or change the vessel’s shape to radar, especially if the rest of the boat is optimized to be quiet on radar.

• Their stealth effect was limited to small size, shaping, and materials

• They would still be detectable by modern naval radars (high tech ones with Western powers), just at shorter ranges.

So, Yes — they can be referred to as “stealth vessels,” but only in a relative and not an absolute sense.

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Edited November 30Nov 30 by நன்னிச் சோழன்

Boat “Docks”

The Sea Tigers of Liberation Tigers did not possess formal harbours to station their naval vessels. Instead, they utilized boat trailers, which functioned as improvised docking systems. These trailers were colloquially referred to as “docks”. Formally, they were called "Padaku Kaavi" (meaning Boat Carrier in Tamil).

Image 1.1: Few boat docks

Image 1.2: A large boat dock

The Sea Tigers maintained a distinct combat and logistics formation formally known as “Padaku Kaavi Ani” (translated from Tamil as Trailer Team). This unit was regarded as the backbone of the Sea Tigers’ naval operations, responsible for the maintenance, transport, and deployment of naval vessels in all naval bases.

The trailers came in various sizes, ranging from small units to larger platforms capable of holding Wave Rider–class vessels and even submarines. This method of improvised docking and concealment was employed from the 1990s onwards.

The boat trailers needed constant repairs and careful maintenance, making maintenance an extremely difficult undertaking. Although the Sri Lankan government imposed a harsh economic blockade on LTTE-controlled areas of de facto Tamil Eelam, the Padaku Kaavi Ani managed to keep the flotillas operational, demonstrating their technical proficiency, commitment, and resilience.

Prior to 1995, the unit was commanded by Major Kaamini (alias Suthakar, alias Jeyaraj), who was killed in action on 7 October 1999 during a naval battle to safeguard procured supplies being transported into the de facto Tamil Eelam via the Mannar Sea from Tamil Nadu. After Major Kaamini was reassigned to serve under the direct command of Brigadier Soosai in 1995, Lt. Col. Annachi, who had previously served under Kaamini, was appointed as the officer in charge of the Padaku Kaavi Ani.

At the time of Lt. Col. Annachi’s appointment, the Jaffna Exodus occurred on 30 October 1995, when over half a million Tamil civilians—men, women, and children—fled alongside the Tamil Tigers as the Sri Lankan military launched Operation “Riviresa-1” (Sooriya Kathir in Tamil) to capture the Jaffna Peninsula. During this crisis, Lt. Col. Annachi oversaw efforts to safely relocate the Sea Tiger vessels to the Wanni region, ensuring their preservation and continued operational use.

When a naval operation or engagement was imminent, the Sea Tigers followed a coordinated launch procedure. The vessels were initially pulled toward the shoreline using tractors, after which they were launched into the sea using tracked bulldozers. These tracked bulldozers came into use in 1996, when the LTTE captured six units from the Sri Lankan Army following the successful defence against Operation Sath Jaya. The bulldozers were personally assigned to the Sea Tigers by LTTE leader V. Prabhakaran immediately after the battle, enhancing the team's launch efficiency and operational capability.

During the early 1990s, before the introduction of such specialized machinery, trailers were moved into the water manually using human force or with the assistance of standard agricultural tractors. This demonstrates the adaptability and resourcefulness of the Padaku Kaavi Ani in maintaining operational readiness despite limited infrastructure and resources.

Image 2: In the early 90s, a Kuruvi class boat with the craft name '004 Nalan' is being pulled into Jaffna lagoon using human force.

Image 3.1: A tracked bulldozer named Keesari is being used for boat launching. The Sea Tigers had at least 6 of these for launching boats.

Image 3.2: Keesari bulldozer shaping the shoreline into a gentle slope for smooth launch.

For a smooth launch, the shoreline sand was excavated and shaped into a gentle slope using the bulldozer earlier. This launch zone was referred to as “Oodu Paathai” (meaning runway in Tamil).

Image 3.3: A Wave Rider class boat is being launched into the shore. The stern side is the one that first touches the water.

While the bulldozer sent in the boats, a rope was attached to the rear of the bulldozer and tied to a tractor to hold the bulldozer steady.

Image 3.4: The rope that's attached to the rear of the bulldozer can be clearly seen in this image

Once the vessels were launched, the trailers (docks) were relocated to concealed positions. After combat operations, the boats returned to shore and were reloaded onto the trailers for transport back to secure inland locations.

However, reloading was often challenging. Due to strong water currents and wave action, aligning the boat precisely with the trailer required multiple attempts. At times, boats had to stand in the sea and wait for favorable tide conditions to successfully dock the vessel. This process could take several hours.

During such delays, the vessels were temporarily hidden near the shore behind natural coastal vegetation and land cover (such as mangrove thickets or tree-lined embankments), which provided limited concealment and some protection from waves. However, this posed a significant operational risk as the vessels were vulnerable to detection by UAVs of the Sri Lankan Air Force and potential airstrikes.

Several aerial attacks took place during these vulnerable periods, commonly from late 2007. One of the notable incidents involved a Wave Rider–class vessel commanded by Lt. Col. Nilavan (alias Maaran), which was struck near the shore in the Kiranji region following a naval engagement off Neduntheevu, Jaffna, on December 12, 2007. This event is considered the first of its kind, as recorded incidents.

During that engagement, the Sea Tigers successfully sank a Dvora-class fast attack craft (hull number P-413) and damaged two more Dvoras, one of which was rendered beyond repair, through a coordinated Sea Black Tigers attack. Four Sea Black Tiger operatives—Lt. Col. Sangkari, Lt. Col. Kalaiyarasi, Major Eezhaveeran, and Major Mathimukilan—were killed in action during this operation. They were the only casualties sustained by the Sea Tigers in that naval engagement.

As the Sea Tiger FGBs were returning to shore and preparing to be loaded onto trailers, they came under aerial attack. One Wave Rider–class vessel was struck near the shoreline, resulting in the deaths of 13 Sea Tiger personnel, including Boat Commanding Officer Lt. Col. Nilavan (alias Maaran), Captain Eekaithee, Captain Thapthaki (alias Inthu), Lt. Akappulavan, 2nd Lt. Chanthana Arivan, 2nd Lt. Kothaikotravan, 2nd Lt. Senthamizharasu, 2nd Lt. Akakkathir, and 2nd Lt. Eezhaththinnan.

The second incident occurred at Alampil sea, Mullaitivu, when a Sea Tigers' Wave Rider class FGB was targeted and bombed when it was near the shore in 2008. The vessel sustained damage but was later recovered and repaired.

Image 4.1: This is the recorded second incident overall, occurring at the Alampil sea. The vessel was not fully damaged, and it can be seen in the right-hand side image. | Image credits: Sri Lankan Air Force

The third incident occurred at Chempiyanpatru, Jaffna, when a Wave Rider–class Fast Gun Boat (FGB) of the Sea Tigers was targeted near the shore in 2008. An aerial bomb fell close to the moving vessel, resulting in damage to the FGB.

Image 4.2: This is the recorded fourth incident overall, occurring at the Chempianpatru Sea on Nov 1, 2008. | Image credits: Sri Lankan Air Force

The fourth incident took place near the Chundikulam estuary. Two Wave Rider–class boats belonging to the Sea Tigers were observed concealed near natural coastal vegetation at the Chundikulam estuary because they couldn't be loaded into trailers immediately after the naval battle. They were detected by a UAV operated by the Sri Lanka Air Force on 8 January 2009 at 07:25 hours and were later aerially bombed and destroyed.

Image 4.3: This is the recorded fourth incident overall, occurring at the Chundikulam estuary, Jaffna. | Image credits: Sri Lankan Air Force

During these vulnerable periods, the Sea Tigers deployed decoys—such as the one shown in Image 5.1—to divert or attract the attention of UAV operators. These decoys were often targeted and bombed, allowing the actual vessels to remain concealed and avoid direct strikes. They were made up of wood and resembled the Wave Rider class vessels.

Image 5.1: A captured decoy of a Wave Rider class boat at Peipparaipitti, Mullaitivu. | Image credits: Sri Lankan Air Force

A recorded video example of this occurred during the Sri Lanka Air Force (SLAF) attack on a Sea Tiger decoy deployed at the Alampil shore in the latter months of 2008. The decoy was targeted and destroyed, allowing the Sea Tigers to relocate their operational vessels safely.

Image 5.2: These images were generated from the above-mentioned video evidence of SLAF targeting a Sea Tigers' decoy at Alampil shore. | Image credits: Sri Lankan Air Force

Additionally, errors during the docking process occasionally resulted in improper alignment, causing the bow hull to strike the trailer structure and sustain damage.

After successful loading, the docks, along with the boats, were moved inland and concealed under tree cover near the naval bases to reduce the risk of detection from aerial surveillance.

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Edited November 17Nov 17 by நன்னிச் சோழன்

Boat Moulds used by the Sea Tigers

The Sea Tigers were known for constructing their vessels both indigenously within the de facto Tamil Eelam and at external locations. During production, they utilized fibreglass moulds to standardize and streamline the boat-building process. Boat construction was managed by two specialized units: the Mangkai Boat Building Unit and the David (alias Shanmukam) Boat Building Unit.

Shown below are some examples of these moulds found in their Theravil Boat Yard.

1) This is an 80-foot-long mould of a boat. The class name or actual image of the boat produced from it is no longer available and has been lost to history.

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2) The class name or actual image of the boat produced from it is not available and lost in history.

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3)

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4) The class name or actual image of the boat produced from it is not available and lost in history. It had an unusual hull form.

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Edited October 25Oct 25 by நன்னிச் சோழன்

Fire Power of the Fast Gun Boats

The subclass name of the Wave Rider class FGB that carried SPG-9 RCL into naval battle remains unknown. This vessel's bow guns were two T-85 Guns.

	Number	Class Name	Subclass	Different types of guns mounted on boats of the Sea Tigers
				Bow Main Gun Mount - 1	Stearn Main Gun Mount -1	Medium-sized Gun Mount - 2/3	Small-Sized Gun Mount - 2/3	Hand Held Guns
	1	Wave Rider	Maathavi (Can carry 7 guns in total)	- 1x ZPU-2 - 1x GIAT - 1x ZU-23 (Single/ double barrel) - 1x 2M-3M/T-61 (Single barrel)	- 1x GIAT  (Only on one vessel named Uthayachchelvi)	- DShK M1938/ T-54/ NSV - .50 BMG - W85 - T-85 - Home assembled T-85 - Mk-19 - AGL-17	- PK GPMG - FN MAG	RPGs of various types.
			Veengkai (Can carry 7 guns in total)	- 1x ZPU-2 - 1x ZPU-4 - 1x 2M-3M/T-61 (Single barrel) - 1xM1939 (61-K)	--
			Mathan (Can carry 5 guns in total)	- 1x ZPU-2 - 1x 2M-3M/T-61 (Single barrel) Other main guns used in this subclass are unknown.	--
			(Subclass name lost in time) (Can carry 6 guns in total)	Eelam War-3:  1x2M-3M/T-61 (double barrel)  Eelam War-4: 1x2M-3M//T-61 (Single barrel)	- 1xZPU-2
			Varman (Can carry 5 guns in total)	Unknown	--
	2	(Class Name lost in time)	-	Unknown	--
	3	Winner	-	- 1xZPU-1 - 1x ZU-23 (Single barrel) - 1x20mm Oerlikon	--
			-	- 1xZPU-1	--
	4	Vellai	-	Unknown	--

Edited October 26Oct 26 by நன்னிச் சோழன்

Conclusion

The Sea Tigers were more than just a rebel movement's naval wing; they were an example of how resourcefulness, self-control, and willpower can transform the battlefield—even at sea. From their improvised origins as the Sea Pigeons to a fleet that could compete with state navies, they personified the LTTE's determination to overcome insurmountable obstacles.

Sea Tigers' strategies—whether they involved underwater sabotage, bomb-laden craft attacks, or lightning-fast attacks—had a profound impact on contemporary naval warfare. Even though Mullivaikkal's collapse in 2009 marked the end of the Sea Tigers, their legacy still captivates historians and analysts, serving as a reminder that nation-states are not the only ones capable of innovating in warfare.

• Note: This article did not include the count on the Sea Tigers' ocean-going fleet

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💬 Author’s Note
Thank you for reading to the end. I would appreciate hearing your thoughts and comments on this work in English.

✍️ Research and Analysis: Nane Chozhan
📷 Image Credits: All images belong to their respective owners. No copyright is claimed.

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