Introducing the Fiobuoy: a submersible all-in-one marine marker buoy designed to redefine safety and efficiency in marine navigation and underwater object retrieval. Developed to address critical challenges faced by maritime industries, enhancing both navigation safety and environmental preservation globally.

Made in Australia

Fiobuoy’s is proudly developed and made in Tasmania, Australia.

Fiobuoy Models

Fiobuoy TD100

Pre-programmed time & date release. Deployable to 100m (328′) Rope capacity: 120m of 10mm line.

Fiobuoy AC100

On-demand acoustic release. Deployable to 100m (328′) Rope capacity: 120m of 10mm line.

Fiobuoy TD200

Pre-programmed time & date release. Deployable to 200m (656′) Rope capacity: 250m of 10mm line.

Fiobuoy AC200

On-demand acoustic release. Deployable to 200m (656′) Rope capacity: 250m of 10mm line.

Why choose a Fiobuoy?

More than just a submerged or pop up buoy, the Fiobuoy is an innovative piece of marine equipment. It will conceal and secure underwater equipment whilst simultaneously allowing for simple and safe retrieval. 

All in one system

Unlike other acoustic release and retrieval systems, Fiobuoys are manufactured as a complete product. With Fiomarine there is no need to source or fit separate components. It is ready for deployment on delivery, therefore lowering your Total Cost of Ownership and ensuring simple servicing and increased warranty protection.

Dependable and Tethered

Unlike traditional acoustic releases that rely on sacrificial weights and can easily become lost in unpredictable currents, the Fiobuoy remains securely tethered to your equipment and anchor. Rest assured, your valuable gear is always right where you left it.

Superior to Surface Marker Buoys

Compared to surface marker buoys that attract unwanted attention and risk being damaged by passing vessels, Fiobuoys maintain your equipment’s security underwater, keeping it completely concealed from the surface. You can even incorporate other equipment within a hallow casting.

Time and Cost Savings

Whether you’re configuring a release and rope canister system or using an off-the-shelf solution, the Fiobuoy saves you both time and money. It comes ready for deployment upon delivery, eliminating the need for sourcing, fitting, and testing separate components. The Fiobuoy was purpose-built as a complete underwater retrieval system, unlike most releases with added rope canisters. Our design, similar to rope manufacturers’ spools, ensures efficiency and minimises entanglement.

Efficient Alternative to Divers

Diving teams may be costly and time-consuming. With Fiobuoy’s complete system, quick deployment, and security code protection, you’ll achieve a far more efficient retrieval method in just a few simple steps. Discover how effortless Fiobuoy operation can be, or witness it in action. Reach out via our inquiry form, and let us show you how Fiobuoy can revolutionize your underwater retrieval process.

Method of operation

Re-deploying the Fiobuoy is a breeze and can be accomplished within minutes after recovery. Simply wind the rope back onto the device and program your desired release time and date, and your Fiobuoy is ready to go. To further streamline this process, Fiomarine offers a selection of rope winders for even quicker redeployment.


A back-up time and date for release is programmed using the handhead terminal.


Your equipment is deployed to the seabed with the buoyant Fiobuoy tethered to it, held fast by the release mechanism.


Upon receiving an acustic command, the realse activates, allowing the Fiobuoy to unwind to the surface.


It ascends at a steady pace while your equipment remains securely tethered at the seabed.


Once the Fiobuoy surfaces, recover your equipment via the tether line.

Key Features

Think a Fiobuoy can assist in securing and retrieving your valuable equipment? Tell us about your deployment and we can recommend and quote the right model for you.

All in one system

Unlike other acoustic release and retrieval systems, Fiobuoys are manufactured as a complete product. With Fiomarine there is no need to source or fit separate components. It is ready for deployment on delivery, therefore lowering your Total Cost of Ownership and ensuring simple servicing and increased warranty protection.

Time / Date Release

Unlike traditional acoustic releases that rely on sacrificial weights and can easily become lost in unpredictable currents, the Fiobuoy remains securely tethered to your equipment and anchor. Rest assured, your valuable gear is always right where you left it.

Acoustic Command Release

Fiomarine’s Acoustic Command Fiobuoys offer greater flexibility with on-demand release. Backed up by all the reliable features of the Time / Date models, Acoustic Command Fiobuoys make retrieving your equipment even easier. By using two way Spread Spectrum Transmission technology and digital signal processing, Fiomarine’s advanced communication system supports re-programming and system interrogation during deployment. It has a standard operating range of up to 500m.

Flexibility in Deployment Depth

100m Deployment

Total possible rope length = 120m (393′) Weight in air (excluding rope) = 15kg Buoyancy in seawater = 3.5kg

200m Deployment

Total possible rope length = 250m (820′) Weight in air (excluding rope) = 19kg Buoyancy in seawater = 8kg

The design of Fiobuoys (likened to a cotton spool) allows for easy modification of these deployment depths and rope lengths. Whether you are deploying in 30m of water or 300m, Fiomarine can adapt our Fiobuoys to suit your needs.

As rope manufactures will attest, the cotton spool design is also proven to be the most effective and reliable way for storing rope and ensures a smooth and tangle free unwinding process.


Customisation, such as rope length, is available upon request to suit your specific application.

No plugs or sockets

Manufactured as a complete product also means your Fiobuoy is protected from leaks. Pre-deployment programming is set up via infra red light, transmitted through the casing. This method was selected over conventional plugs and sockets which not only leak but also corrode in many marine environments.

Password Protected

Each individual Fiobuoy is encoded with a six-digit pin number to prevent unauthorised use. This also enables each Fiobuoy in a fleet to be accessed and commanded individually via acoustic communications.

Extended Battery Life

Fiobuoys have no ON / OFF switch. Instead, the Fiobuoy’s onboard computer is kept in a constant ‘sleep’ mode, except for its daily, self-diagnostic operation. This not only substantially lowers power consumption and prolongs battery life, but also provides further protection from leaks. Following an ‘awakening’, ‘sleep’ mode is automatically re-entered following a predetermined period of inaction.

Robust Construction

The housing of the Fiobuoy range is manufactured from highly durable polymers capable of withstanding the rigours of the harshest marine environment. For defence applications, Fiobuoys have been tested to withstand an explosion of 5kg of TNT within 10m, proving its durability.

Hollow Casing

Fiomarine’s 200m Fiobuoy has a hollow casing to allow for easy incorporation of customer specific equipment.

Full Two-Way Communication

The Fiobuoy AC100 and AC200 support 2 way communication, enabling confirmation of commands received and system interrogation during deployment. These can also act as underwater communication platforms for transmission of data.

Performs Self-Diagnostics

Fiobuoys constantly review the condition of their on-board batteries to ensure the availability of sufficient power to perform a release event.

Minimised Marine Growth

Fiomarine’s patented release mechanism is designed to specifically inhibit marine growth. When the mechanism’s ‘jaw’ is opened any marine growth is forcibly removed, thus increasing its reliability.

Protection from Rope Entanglement

The Fiobuoy range was specifically designed to perform a slow ascent to the water’s surface, minimising the risk of rope entanglement.

Performs Emergency Release

During its daily battery check, by default Fiobuoys will perform an ’emergency release’ when there is a risk of the batteries losing their energy prior to the scheduled release time / date. This feature is also designed to prevent deployment where the battery voltage is considered too low.

Capable of Leak Detection

Although all Fiobuoys in the range are heavily protected from leaks, the on-board electronics incorporate leak sensors. Upon detecting the presence of water in the central chamber the sensors will actuate the release mechanism to perform an emergency release to ensure retrieval.

Frequently Asked Questions

Unable to find the answer to your questions? No worries, please get in touch and we’ll be able to recommend the most suitable Fiobuoy model for your deployment.

How is the Fiobuoy different from other acoustic release systems?

The Fiobuoy is different from traditional acoustic releases because it combines a release, surface marker, retrieval line and storage, all in one product. Read an in depth analysis of the major differences on our Fiobuoy v Acoustic Release page.

Is the Fiobuoy protected against rope entanglement?

The Fiobuoy is designed specifically to combat rope entanglement. Its design replicates the method rope manufacturers use to supply rope; the simplest and most effective way – on a spool. Rope released from a canister can get easily tangled, whereas the Fiobuoy unwinds naturally, and our Winders make for simple and fast re-deployment.

Am I limited in the type and length of rope I can use?

The design of the Fiobuoy makes it easy to customise the rope for your specific deployment needs. Our TD100 & AC100 models, which are rated to 100 metres, can accommodate a maximum of 120m of rope. While our TD200 & AC200 models can fit a maximum of 250m all using 10mm diameter rope.

We supply two types of rope: 10mm Asiadragon three strand, with a breaking strain of 1,500kg, and 10mm Navy Braid with a breaking strain of 5,000kg. Provided it is neutrally buoyant, you can also supply your own rope.

How can I be sure the Fiobuoy will surface in high currents?

In the ocean all bodies are affected by high currents but the unique dynamics and design of the Fiobuoy means it works differently to normal floats and acoustic releases.

Provided your Fiobuoy has an excess of rope for your deployment depth, your Fiobuoy will surface. Once surfaced, for the period of time it takes for the remaining line to unwind from the spool, you have time to retrieve it. This is because during this time the Fiobuoy is effectively an untethered free-floating body which will not be dragged under by currents (unless they are extremely strong).

Also the Fiobuoy’s unique ‘unwinding’ principle means it doesn’t need to drag or pull the full length of line through the water column. This combined with the fact that at the time of ‘unwinding’ the Fiobuoy doesn’t lift anything but its own weight means it rises to the surface easily. 

Is the Fiobuoy suitable for both salt and fresh water deployments?

The design and dynamics of the Fiobuoy make it suitable for both salt and fresh water deployments i.e. oceans, rivers and lakes etc.

Is the Fiobuoy difficult to maintain and service?

The Fiobuoy requires only minimal and simple maintenance, which can be carried out by the user. Depending on its use, the Fiobuoys Battery Pack need only be changed every 3-6 months for the acoustic models, and 12 months for the Time/Date. Currently the battery packs use high quality alkaline cells with standard battery pack construction. Fiomarine can supply packs, or provide technical details for local construction by qualified agents.

At the time of battery replacement the Fiobuoy’s o-rings can also be replaced, and your Fiobuoy is ready for deployment again. A Maintenance Kit includes everything you need. O-ring replacement is typically recommended every 12-24 months depending on inspection.

How do you protect against fouling on the Fiobuoy’s release?

The Fiobuoy’s release mechanism is designed in a way to ensure fouling does not affect its release. Many acoustic releases are designed with a mechanical arm, so when they are opened debris and seaweed etc can get caught on the arm preventing the line to be released. The Fiobuoy was designed with a jaw and ball-pin, not an arm. This means that when the release is actuated the jaw opens, releasing the pin and pushing any growth away.

What is the Fiobuoy’s lifespan?

Fiobuoys are built to last a minimum of 10-15 years. Our very first models ever made (more than 20-years-ago) are still in perfect working condition, and still being used by the Royal Australian Navy.

Can I use other battery types?

Currently we use alkaline batteries which have a life of approximately 3-6 months or 12 months, depending on your Fiobuoy model and usage patterns.

Will the Fiobuoy still work in extreme temperatures?

The Fiobuoy’s mechanics, plastics and electronic systems will not be affected by extreme temperatures. We have customers successfully deploying Fiobuoys in areas ranging from near freezing in the Arctic Ocean off Canada to 26°C in the Pacific Ocean off Papua New Guinea.

Will the Fiobuoy’s acoustics interfere with my other equipment?

The Fiobuoy’s acoustic system transmits less than 1 watt into the water. It is highly sophisticated and due to its Spread Spectrum technique is almost undetectable by other systems.

As a result equipment such as ADCPs will not be affected, nor will such systems affect the Fiobuoy’s communications.

Is your Deck Control Unit compatible with other releases?

No it isn’t. After researching this option we found that many multi-brand compatible systems try to do too many things and ultimately end up not doing any of them particularly well. We have concentrated on making our system the most reliable on the market. To ensure this, we use highly sophisticated encoding and Broad Band Spread Spectrum technology, making our Deck Control Units integral and specific to the functioning of Fiobuoys only.

What frequency does the acoustic signal transmit on?

Unlike traditional acoustic communications equipment, the Fiobuoy’s system uses advanced digital signal processing employing Broad Band Spread Spectrum techniques (similar to mobile phones). This means the transmitted energy is ‘spread’ over a range of frequencies, typically 14 kHz – 31 kHz for the Fiobuoy. This has the advantage of overcoming real world impediments such as Doppler shift and signal bounce due to temperature or salinity layering or marine life.

The system is not the traditional simple signalling system, but a full, two-way confirmed-packet protocol enabling modem to modem communication.

Can I use one Deck Control Unit to activate more than one Fiobuoy?

Yes, each Fiobuoy has a six digit security access code, and with the acoustic models this also acts as your communications address. Our standard Deck Control Unit can be set to access any single Fiobuoy in your fleet. There is no global broadcast function.

What is the range of the acoustic system?

We have limited the Fiobuoy’s acoustic range to a distance of 500m line-of-sight. This is primarily because at no stage is the Fiobuoy untethered from its anchor, so it will always be at the original drop site. With GPS devices, users can usually be certain of being within a few tens of metres, well within the 500m range. We can also supply systems of 1km distance or greater on request.

Is the Fiobuoy’s jaw and pin strong enough?

In traditional acoustic releases, the release mechanism needs to support the payload weight. Whereas, with the Fiobuoy, the rope (with a breaking strain of 5,000kg) not the jaw and pin, holds this  weight. The Fiobuoy’s jaw and pin only needs to hold a maximum of 8kg of buoyancy plus some tidal drag. The jaw and pin has also been tested to withhold several times this load.

If there is a reduction in buoyancy whilst the Fiobuoy is submerged, could the rope slip?

Whilst the Fiobuoy is submerged, the rope (held securely by the jaw and pin), sits between the Fiobuoy’s handles. In order for it to slip, there would need to be a significant and sustained force pushed downwards directly on the Fiobuoy. This force would need to counter the Fiobuoy’s own bouyancy of 3.5 or 8kg.

If this were to occur – although unlikely – the worst case scenario would see the rope merely slip between the next handles, remaining tethered and the jaws securely closed.

Further information


Fiomarine offers a range of accessories to make your deployments simpler and faster.


The Fio GMS1000 is a unique, easy-to-use gas management system that provides for economical, safe and controllable flotation and retrieval of extremely heavy loads.

Fiobuoy Vs Acoustic Release

The Fiobuoy combines an acoustic release, floatation, surface marker, retrieval line, and line storage, all in a unique buoy design.