---
title: "Batteries, a cable, and one service visit a year"
url: https://mru.space/use-cases/deep-sea-observatories/
description: "Seafloor nodes run on batteries or cable with about one ship visit a year. Mru Field keeps them delivering checked data as processors fail between visits."
---

[Mru](https://mru.space/) / [Mru Field](https://mru.space/field/) / [Use cases](https://mru.space/use-cases/) / Deep-sea observatories

Ocean · Seafloor Pilot planned

# Deep-sea observatories

Batteries, a cable, and one service visit a year.

![TEMPO deep-sea observatory module on a hydrothermal vent](https://mru.space/_astro/pl01-tempo-observatory.pX0As2E2_Z9udeN.jpg)

TEMPO deep-sea observatory module on a hydrothermal vent Ifremer · CC BY 4.0

1visit / year

EMSO-Azores runs on batteries 1,700 m down. A ship comes about once a year.

EMSO ERIC · EMSO-Azores

Seafloor observatories run science nodes on batteries and cables, far below anyone's reach. When a computer fails between visits, the data stops until the next ship.

Mru Field runs on the processors already in the equipment. When one fails and nobody can come, it continues on the ones left and delivers only results it can check. Status: decision core at TRL 3; first field pilot planned for 2027.

01

## Computers fail one by one

Radiation, heat and age take out processors and memory. Nothing is replaced until the next visit.

02

## Power runs down

Batteries fade and panels foul. The system has to do less, on purpose, and keep the important part going.

03

## No one to ask

When two computers disagree, there is no operator to say which one is right.

## Three computers. Then two. Then one, still working.

Most redundant systems stop when they lose their majority. Mru Field steps down instead, and says which mode it is in.

3 alive · vote

A B C

Three computers vote. One bad result is outvoted.

2 alive · compare

A B C

Two compare. A known-answer test finds the faulty one.

1 alive · self-check

A B C

The last one checks its own work and keeps logging until the ship comes, at half speed.

Power

Batteries or seafloor cable

Link

Cable or acoustic, intermittent

Visits

About once a year

Service life

Years per deployment

## Questions

Does Mru Field need new hardware?

No. It is software for the processors you already deploy. It runs beside your control code and decides which computer to trust as parts fail.

Is there a test site?

We plan a pilot in the Azores in 2027.

How do we start?

Use the form below. We first model your hardware and show what each redundancy design returns over its whole life. Then we plan a pilot on your own equipment.

## Related settings

[All use cases](https://mru.space/use-cases/)

[

Ocean · Surface

### Ocean buoys and moorings

](https://mru.space/use-cases/ocean-buoys/)[

Ocean · Autonomous

### Profiling floats and gliders

](https://mru.space/use-cases/profiling-floats/)[

Ocean · Vehicles

### Autonomous underwater vehicles

](https://mru.space/use-cases/auv/)