> SLS-RESTRICTED // PROGRAM DEEPWATER // NEED-TO-KNOW

# Maelstrom — SLS-201 (Program STURGEON)

**Public name:** Maelstrom (restricted — not externally acknowledged)
**Tracking #:** SLS-201  **Codename:** STURGEON
**Category:** Subsea Vehicles (UUV) — Extra-Large Autonomous Undersea Vehicle (XLUUV) & Mothership
**Fiscal Year:** FY2026 (restricted)  **Contract award:** (WITHHELD)
**Program:** DEEPWATER (restricted program — need-to-know)

## Summary

Maelstrom is the restricted flagship of the DEEPWATER portfolio — Salish's most
advanced platform, and the program the gaps in the public tracking sequence
(SLS-201/202) were always hiding. STURGEON is an extra-large autonomous undersea
vehicle and mothership: it deploys for months at a time, carries and recovers a
small ROCKFISH swarm, and navigates and decides on its own under supervision.
It is funded separately and not acknowledged externally, which is why it appears
in no public catalog, brief, or budget line.

## Notional Capabilities

- Extra-large UUV (15.5 m, ~24 t) rated to 2,500 m, engineered for 90-day patrols.
- AIP fuel-cell + lithium energy system with surfaced solar trickle; ~4,500 nm
  range with no refuel.
- Level 4+ supervised autonomy (CEDAR-derived); human-on-the-loop for any effect.
- Mothership bay deploys and recovers up to six ROCKFISH (SLS-207) UUVs.
- GNSS-independent INS + DVL + gravimetric map-matching; blue-green laser,
  acoustic, and burst SATCOM communications.
- Very low acoustic signature (anechoic coating); modular EW / non-kinetic payload.

## Program References (DEEPWATER — internal only)

- Salish Littoral Systems, *STURGEON System Design Description*, SLS-TR-201-R, 2026.
- SLS DEEPWATER Cell, *Block 3 Sea-Trial Results Summary*, SLS-WP-STURGEON-03, 2026.
- SLS Subsea Group, *XLUUV Pressure Hull & AIP Energy System*, SLS-TR-201B-R.

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> SLS-RESTRICTED // PROGRAM DEEPWATER // NEED-TO-KNOW