Ukrainian defence firms have publicly presented the Toloka family of unmanned underwater vehicles (UUVs), including a large-diameter model said to be capable of carrying a five-tonne payload over a distance of up to 2,000 kilometres.

The systems were shown at the Brave1 Defence Tech Valley 2025 exhibition in Lviv on 19 September.

Toloka comprises at least three variants aimed at short-, medium- and long-range missions. According to technical information shared by the developers and summarised by Defence Express, the series includes the TLK-200, TLK-400 and TLK-1000.

The firm states that the drones are designed for tasks such as reconnaissance, mine countermeasures, seabed mapping, communications relay and strike missions. The specifications below are as published by the developers; none has yet been demonstrated in combat conditions.

TLK-200 (short-range). This compact, electrically powered UUV is listed with a range of up to 100 km, endurance up to 15 days and an operating depth of up to 300 m. The hull measures 2.9 m in length with a 200 mm diameter. Stated payload is up to 15 kg. Navigation is via GNSS and an AI-assisted inertial system; guidance options include optical or thermal imaging and homing on radio-frequency sources. Communications can be maintained through a satellite link using frequency-hopping (FHSS).

TLK-400 (medium-range). The TLK-400 moves to a hybrid powertrain (four electric motors plus an internal-combustion unit) and is listed with a range of up to 1,200 km, endurance up to 60 days and an operating depth of up to 300 m. The published dimensions are a 400 mm diameter and 12 m length, with a payload capacity up to 500 kg. Guidance and navigation suites expand to include passive/active acoustics alongside electro-optical options.

TLK-1000 (long-range/heavy payload). The largest variant, with a published diameter of 1.5 m and length of 12 m, is described as a long-range UUV for the delivery of up to 5,000 kg of payload over as much as 2,000 km. Endurance is listed at up to 60 days. Operating depth depends on hull material: up to 300 m for a composite hull or up to 30 m for a metallic hull. As with the smaller models, the TLK-1000 integrates autonomous mission-planning systems, GNSS and AI-assisted inertial navigation (including Doppler Velocity Log), multiple guidance modes (optical, thermal and RF homing) and satellite communications with FHSS.

The unveiling follows earlier references to Toloka by Ukrainian officials. Media reports note that President Volodymyr Zelensky highlighted the programme in February, and that the General Staff promoted the Lviv display on 19 September. Coverage also points to Ukraine’s ongoing incorporation of maritime drones into Black Sea operations since 2022.

Analysts have drawn attention to the potential implications for Russian infrastructure in and around occupied Crimea. The Kyiv Independent reported that the TLK-1000’s range and payload, if validated, could pose a threat to the Kerch (Crimean) Bridge, a key supply route for Russian forces. The outlet also noted that Ukrainian forces have already carried out multiple attacks against the bridge and other Black Sea targets using unmanned systems. These assessments remain contingent on independent verification of the Toloka systems’ performance.

RBC-Ukraine’s account of the Lviv presentation stated that three configurations of the TLK-1000 were shown, ranging from approximately four to twelve metres in length, and reiterated the 2,000 km strike envelope and five-tonne payload claim. The report further cited expert commentary suggesting that several heavy UUVs could, in theory, be used against large fixed structures. Again, these are claims and scenarios offered by commentators; Toloka’s operational use has not been confirmed.

The Toloka line appears to extend Ukraine’s shift from surface-skimming uncrewed boats to submerged systems intended to reduce detectability and increase flexibility of approach. Endurance figures of up to two months, hybrid propulsion, and multi-mode guidance would, if realised, broaden mission options from mine countermeasures and reconnaissance to long-range interdiction against port infrastructure or anchored vessels.

However, several factors will determine practical effect: production scale, integration with targeting and command-and-control, resilience to electronic warfare and anti-UUV defences, and the capacity to navigate contested littoral waters without loss of communications. These aspects are not yet publicly evidenced.

In summary, Ukraine has set out an ambitious underwater drone capability centred on a modular family with published ranges from 100 to 2,000 km and payloads from 15 kg to 5 tonnes. The technical package—autonomous navigation, acoustic and electro-optical sensing, and satellite communications—aligns with current UUV trends. The strategic significance, including any impact on Russian maritime logistics and fixed infrastructure, will depend on how these systems perform outside the exhibition hall.