SUBSURFACE OPERATIONS

BIFROST

Unlimited Underwater Endurance for Special Operations Divers

Every combat diver in JSOC, NSW, MARSOC, and Force Recon faces the same constraint: gas runs out. When it does, the mission ends — regardless of whether the objective is complete.

BIFROST eliminates that constraint entirely by harvesting breathable gas from the surrounding ocean. For the first time, a combat swimmer can remain submerged indefinitely without pre-staged gas supplies, surface support, or logistics coordination.

The operational implications: extended covert beach surveys, unlimited ship-bottom operations, subsurface infiltration routes that bypass every surface detection system, and diver-delivered payloads at ranges currently impossible.

THE PROBLEM

Combat divers operate under a single, hard ceiling: finite gas supply. The LAR-V — the US SOF standard — is depth-limited by oxygen toxicity. The MK-25 UBA is heavier and requires extensive gas-fill logistics. Both end the mission when the cylinder runs out.

Surface support craft increase the unit's signature and risk. Beach reconnaissance is truncated. Hull-attack windows are halved. Subsurface infiltration is constrained to what a diver can carry on their back — and what they can carry is the bottleneck for everything operationally downstream.

BIFROST removes the bottleneck. The diver no longer plans around the gas — the ocean is the gas.

CAPABILITIES

Covert Insertion

Zero acoustic, visual, or thermal signature. No bubble trail for sonar, no surface disturbance for FLIR. Combat swimmers become undetectable during subsurface transit.

Unlimited Duration

SOF dive missions currently limited to 4-6 hours by gas volume. BIFROST removes the gas ceiling. Mission duration limited only by the operator and scrubber — not supply.

Depth Advantage

Performance improves with depth. Enables sustained operations at depths that would rapidly deplete conventional rigs, opening new mission profiles for MCM and subsurface ISR.

Zero Logistics

No gas fills, no cylinders, no shore-side infrastructure. A SEAL platoon deploys with BIFROST and operates indefinitely from any coastline without resupply.

MISSION PROFILES
Beach Reconnaissance
Multi-day hydrographic survey without surface support
Hull Attack
Sustained ship-bottom operations — limpet, sweep, search
Mine Countermeasures
MCM diving at depths beyond LAR-V O2 toxicity limits
SDV Lockout Extension
Extended free-swim ops after vehicle deployment
Subsurface Infiltration
Long-range covert approach to denied targets
Underwater EOD
Indefinite hold on hazard until safe to action
Pier & Harbor Ops
Choke-point ISR without surface signature
Lock-In / Lock-Out
Submarine egress operations without time pressure
OPERATIONAL SCENARIOS

Extended Subsurface Infiltration

A SEAL platoon conducts a 14-hour subsurface approach to a hostile port facility. No SDV support, no surface craft. Operators enter the water 12 nautical miles offshore and arrive undetected, rested and mission-ready. Current systems: impossible beyond 4-6 hours.

72-Hour Covert Hydrographic Survey

A two-man dive team maps the seafloor approach to a denied harbor over 3 days, surfacing only for rest. No gas resupply, no support vessel loitering in hostile waters, no signature.

Unlimited Hull Operations

EOD divers conduct ship-bottom searches on anchored vessels for indefinite periods without time pressure. No emergency ascent because the clock ran out. The mission ends when the job is done.

vs. CURRENT SYSTEMS
Dräger LAR-V
MK-25 UBA
BIFROST
Weight
14 kg
30+ kg
< 12 kg
Max Duration
4 hours
6 hours
Unlimited*
Gas Supply
Finite (O2 cylinder)
Finite (mixed gas)
Continuous (ocean)
Depth
21m (O2 toxicity)
91m
Scales with depth
Signature
None (CCR)
None (CCR)
None
Logistics
O2 fills + soda lime
Gas fills + scrubber
Scrubber only

*Limited by CO2 scrubber endurance (3-6 hrs per canister) and operator physiology, not gas supply.

<12kgSystem Weight
0Signature
30m+Operating Depth
3-6hrPer Scrubber
ECOSYSTEM INTEGRATION
MIMIR
Manages life-support parameters in real time — setpoints, scrubber saturation, dissolved-gas flux. Alerts before sensors detect a problem.
LIMITING FACTOR
Trains the operator who will use BIFROST — combat swimming, water confidence, dive physiology under load.
SINDRI
Hardens the firmware and control software against compromise. Adversary cyber threats apply to defense hardware too.
FAQ
How does the noise signature compare to a LAR-V?
Equivalent on the breathing loop — both closed-circuit, no exhaust bubbles. The harvesting subsystem adds no measurable acoustic signature.
What about decompression?
Standard CCR profiles apply. The harvested gas is enriched air; ppO2 is regulated by setpoint identical to existing rebreathers.
Is this ITAR controlled?
Yes — USML Category XIII(b). Distribution restricted to authorized recipients.
What happens if the harvesting subsystem fails?
Onboard reserve gas (bailout) maintains the diver until ascent. The system fails safe.
When could a unit field this?
Fielding follows standard SBIR Phase II → III pathway. AFRL/AFWERX is the current target program.
ORIGIN

Built by Gage Ludwig — Air Force EOD technician — and Clarice Zimmerman, mechanical engineer. The constraint was lived. The solution was engineered. AESIR was founded to remove the gas ceiling because no current rebreather will, and the next generation of combat divers shouldn't have to plan around that limit.

THE NORSE CONNECTION

BIFROST is the rainbow bridge in Norse mythology — the path connecting Midgard, the realm of humans, to Asgard, the realm of the gods. The bridge between worlds. Our BIFROST does the same: it bridges the world above water and the world below, letting the operator move freely between them without the constraint that has always defined that boundary.

STATUS

Architecture complete. In development under ITAR. Targeting AFRL/AFWERX SBIR Phase II. Designed for Naval Special Warfare, MARSOC, and any SOF element conducting subsurface operations.