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Fetch AZA

Self-calibrating bottom pressure recorder

Engineered for: Seabed

Fetch AZA revolutionises seabed measurements, across ocean science and the commercial sectors. It's now possible to record high-resolution data from a self-calibrating sensor, at all depths, for long durations of up to 10 years.

At a glance

Self-calibrating for accurate environmental monitoring

Long life—up to 10 years battery life

3,000 and 6,000 m depth options

Easy to deploy, easy to recover

Can be configured with a wide range of sensors

Integrated acoustic modem for data recovery

Low cost in-situ ocean surveillance

Want to know more?

Command and control from a vessel or USV

Engineering using industry-standard glass spheres, trusted globally

Patented self-calibrating system ensures pressure sensors never drift

Integrated acoustic release mechanism for easy recover after survey

Why Fetch AZA is perfect for your operations


Data from Fetch AZAs can be recovered using USVs from over-the-horizon meaning you no longer need a dedicated crewed vessel with associated costs and emissions.


The high quality pressure sensor is automatically recalibrated in situ allowing consistently accurate readings over a deployment period of up to 10 years.


Fetch AZA makes detecting and recording centimetric horizontal and vertical movement achievable and repeatable over time.


Unlike traditional pressure sensors, which suffer from drift over time, our Fetch AZA technology autonomously recalibrates in situ.

A unique control system periodically cycles the pressure sensor from ambient seabed pressure to near-zero, enabling comparison to a highly accurate low-pressure reference sensor for calibration. The reference sensor is never subjected to ambient pressure and is accurate to changes of less than a millibar, or about 1cm of head of water.

These capabilities have created an instrument that revolutionises seabed measurements, across ocean science and the commercial sectors. This means that scientists can now undertake measurements, at a resolution they’ve never been able to achieve before. These are critical to understanding tectonic processes.

In the commercial sphere, Fetch AZA now meets upstream production companies’ long-term goal of measuring 1cm/year of vertical movement across their fields. Such fine-scale measurement provides a powerful new tool for proactive reservoir management. This is a key enabler for maximizing economic recovery.

The sensors are low power, allowing for long endurance deployments, and provide time-stamped data, which is often critical to commercial and scientific objectives. With their in-built data storage and high-speed modem capacity, they can support data collection and harvesting using a wide range of other Sonardyne and third-party sensors (High precision temperature and sound velocity as well as inclination) and are compatible with any Sonardyne 6G equipment, including Ultra-Short BaseLine (USBL) systems and modems.

Why invest


  • Well suited for USV data harvesting

  • Can be configured with a wide range of sensors

  • Different deployment and recovery options provide flexibility for your operations


  • Neutral buoyancy in water for easy recovery

  • Anti trawl frame option available

  • Glass sphere, duplex s/steel guard, PVC shell, titanium ports construction


  • 3,000 m and 6,000 m depth rated versions

  • MF and LMF operating frequency options

  • Up to 10 year battery life

  • Self-calibrating pressure sensor


  • Work side-by-side with our Projects Group from concept to deployment

  • Systems are manufactured and tested before delivery at our world-class in-house facilities

  • Work with our experienced team about our USV data harvesting service

  • 24-hour support, whenever and wherever you are in the world


Feature Type 8306
Depth Rating 3,000 m
Operating Frequency MF (20–34 kHz)
Transducer Beam Shape Directional/omni-directional
Transmit Source Level (dB re 1 µPa @ 1 m) 190–202/187–196 dB
Receive Sensitivity (dB re 1 µPa) <85 dB
Communications Acoustic modem & Bluetooth wireless
Battery Life (Lithium) 10 years typical, (504 Ah) (dependent on sensors and sampling interval)
Mechanical Construction Glass sphere, duplex s/steel guard, PVC shell and titanium ports
Operating Temperature -5 to +35°C
Storage Temperature With Batteries 0 to +30°C
Without Batteries -5 to +35°C
Mass With Stand 145 kg
Without Stand 62 kg
Weight in Water With Stand 830 N
Without Stand 25 N (negative buoyancy)
Sensors and Options
AZA In-situ Self-Calibration Mechanism Standard
High Precision Temperature Sensor (±0.015°C) Standard
Transfer Pressure Sensor Quartz, (±0.01%) Standard
2nd Quartz Option
Ambient Pressure Sensor Strain Gauge, (±0.01%) Standard
Strain Gauge, (±0.19%) Option
Low-Range Pressure Sensor (Strain Gauge, 2 bar (±0.01%)) Standard
Sound Velocity Sensor ±0.02 m/s Accuracy Under Calibration Conditions Option
MEMS Inclinometer (±1°) Standard
High Precision Inclinometer (±0.05°) Option
Acoustic Baseline Ranging1 Option
Release Mechanism (Screw-off) Option
Battery Disconnect Fob Standard
Stand/Mud Feet Option

Manuals and quick start guides

Software and firmware

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Low cost in-situ ocean surveillance