Helsing

SG-1 Fathom (with Lura)

In Trials / Early Production

A ~2 m, ~60 kg autonomous underwater glider that patrols for up to three months running Lura, a 'large acoustic model' trained on decades of ocean sound to detect and classify ships and submarines. Deployable in swarms as affordable persistent undersea surveillance; built in Plymouth for the Royal Navy's Atlantic Bastion program.

Latest update Sep 17, 2026

SG-1 Fathom (with Lura)

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Current status

At-sea trials completed 2025 incl. Royal Navy swarm deployments in the Hebridean Sea; Plymouth factory producing since Nov 2025; full operational capability still targeted end-2026 with no FOC announcement as of September 17, 2026

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Specifications2

Endurance
Up to ~3 months submerged patrol
Size

~2 m long, ~60 kg, containerized and rail-launchable

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Upcoming milestones1

Announced next steps from Helsing that mention SG-1 Fathom (with Lura).

  1. Q4 2026

    SG-1 Fathom reaches full operational capability with the Royal Navy

    After Hebridean Sea swarm trials and the December 2025 launch of the UK's Atlantic Bastion undersea-surveillance network, hundreds of Plymouth-built Fathom gliders are to reach full operational capability by the end of 2026. The Royal Navy held further supplier demo days for the wider undersea-surveillance programme in April 2026. Re-checked on September 17, 2026 against Helsing's Fathom product page, Royal Navy Atlantic Bastion coverage, and recent news: no FOC date has been announced and the end-2026 target is unchanged. Watch for the first sustained North Atlantic ASW patrols and any follow-on orders from other NATO navies.

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