Frequently Asked Questions

What is a GNOM?
GNOM is a remotely operate vehicle (ROV) that has been developed by Russian designers. This acronym is a transliteration from Russian "ГНОМ" which means deep-water remotely operated survey micro robot. The second meaning of this word in Russian is "dwarf".
How do I place an order?
Please contact to our managers. They will provide you all the information and answer all your questions. Normally you approve the modification and the whole system set and then sign a contract. All ROVs and additional equipment must be prepaid. You can negotiate details with our managers.
Do you provide service or training?

Service and training are provided by the producer or dealers. The list of dealers can be found here. Because of its extreme simplicity in most cases all required service can be done buy the owner. All basic skills you can get directly from the dealer. Training will not take too much time.

How many people are needed to operate ROV GNOM?
Even one person can operate the vehicle. Two people may be preferable in case of extreme conditions.
What are the main differences between ROV GNOM and analogs?

Few small sized ROVs designed for survey operations have been developed by other companies. 
Advantages of ROV GNOM in comparison with other ROVs:
- All analogous ROVs have more powerful thrusters and consume more energy. Thick cable (10- 12 mm in other  ROVs instead of 3 mm in ROV GNOM) is required more power  of such vehicles. In operations at depths they spend much more energy for  cable drawing.
- ROV GNOM has smaller size than all other analogs. At the same time it can carry different additional equipment and operate in closed and hide-to-reach places. Only one person may operate ROV GNOM from any kind of boat (even from small rubber boat). ROV GNOM is a real “personal ROV”.
- ROV GNOM has high equipment compatibility. Joystick, monitor, connected cables, video recorder can be bought in the regular store.
- ROV GNOM  has the code certificate (Russian and CE) of electrical safety and electromagnetic compatibility.

How can I buy the ROV GNOM?
First you have to sign the purchase and sale contract. We can deliver all equipment via mail or you may pick up your order at the closest dealer.
What are the limitations of ROV GNOM use?
* Current velocity more than 1 m/s (for GNOM standard and Super GNOM). Up to 2 m/s current velocity is permissible during the Super GNOM Pro operations.
* Zero visibility. In such conditions you may use multibeam high resolution sonar (Didson, Blueview) in addition to the regular video camera.
* High level of radioactivity. Special protection for the camera and electronics must be installed on the vehicle for operations in conditions of high radiation.
* Air temperature below zero. LCDs are commonly used as output devices for video signal. Negative air temperature restricts the use of LCD. The temperature range of the vehicle operation is –20…+45 ?C.
What are the depth limitations of ROV GNOM?
The cable length and water pressure are the main limitations of operating depth. Basically the operating depth of ROV GNOM is 150 m with a cable length up to 200 m. We can increase a vehicle operating depth up to 750 m upon request.
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Can ROV GNOM perform any underwater operations except survey operations?
Besides survey operations ROV GNOM can perform rescue operations, take samples and measure various environmental parameters. For such needs additional equipment may be installed on ROV.
Do I need to take special classes to learn how to operate ROV GNOM?
You can get all basic skills operating ROV GNOM during 1 hour. You may need more experience to operate the vehicle under unusual conditions.
How much additional weight (equipment) can be installed on ROV GNOM?
The weight of additional equipment depends on the size of floating module which makes the vehicle neutrally buoyant. Excessive increasing of floating module will significantly decrease speed and maneuverability of the vehicle. The optimal additional weight (in the water) for Super GNOM is 0,5 kg (~30% of cruise thrust). Up to 5 kg (submerged weight) of equipment can be installed on ROV Super GNOM Pro.
What additional equipment can be installed on the ROV GNOM?
Manipulator (grabber), rotation-type scanning sonar, hydroacoustic navigation system, depth sensors, temperature and salinity sensors, laser pointers and additional video camera can be installed on the ROV GNOM. In some cases magnetometric system, spectrograph or other specific equipment can be installed. The main limitations of additional installed equipment are size and weight.
What is the cheapest and most upgradable modification of ROV GNOM?
GNOM standard is the basic modification of ROV GNOM. Replacement of electronics module and thrusters leads to the Super GNOM modification. Manipulator and hydroacoustic equipment can be installed on this more powerful vehicle. However such upgrade may be more expensive than a new robot. Super GNOM Pro is the most upgradable vehicle among all GNOM modifications.
What is the repair kit for? What does it contain?
ROV GNOM is a complex high-tech robot which has to operate in extreme conditions such as high moisture, salinity and temperature gradient. ROVs require minimum essential periodic maintenance. The full description of preventive maintenance can be found in the user's manual. Repair kit basically includes bearings, o-rings, lubricant, propellers etc.
Is it possible to install the hydroacoustic navigation system on ROV GNOM?
Yes, the hydroacoustic navigation system can be installed on Super GNOM or Super GNOM Pro.
What else should I have for ROV GNOM operation?
Image output/record device (may be included into system set), 12VDC battery (may be included into system set) or power supply 220VAC, 50GHz.
Do I need a scuba diver during the ROV GNOM deployment?
Scuba diver is not absolutely required for ROV GNOM operation; however it can ensure the vehicle from any kind of damage.
Do I need a power supply, what kind?
ROV GNOM requires 12VDC battery (may be included into system set) or power supply 110-220VAC, 50-60GHz
I need a real-time video recording during the ROV operation to map the sediment types of the bottom. Can ROV GNOM perform such investigation?
Basically such operation is possible. ROV GNOM has an analog output, which means that there is no time lag during the signal transmission. Video-data processing normally takes few milliseconds. The quality of the record will depend on your computer.
Is it possible to make a ROV without a cable?
AUV (autonomous underwater vehicle) is a type of underwater remotely operated vehicles without a cable. However such vehicles have been developed for different purposes. The hydroacoustic channel is not sufficient for the high resolution video transmission underwater. That is why AUVs are inappropriate for underwater survey operations.
What type of data carrier/recorder do I need? Is it included into the system set?
You can use any type of data carrier/recorder with RCA jack such as analog or digital recorder, video camera or laptop. Any of these devices may be included into the system set upon your request. Usually we suggest a portable digital recorder such as Archos AV700.
Is it possible to survey and record the half flooded tunnels?

Additional video camera can be installed on the top of the vehicle. This camera allows to survey above the water level.

Is it possible to watch the real-time video at the laptop screed and record the video signal by the digital camera via USB-cable?
Yes, but the laptop must have all required characteristics
How controlling commands are transmitted to ROV GNOM? How many cores are in the cable?
The control module is connected with the vehicle via single-core coaxial cable. This cable is used for power supply (24V to 180 V), transmission of analog video signal and digital controlling signals (commands). 16-but microprocessor controls the data exchange. This unique technology developed by ROV GNOM designers allowed production of extremely thin cable.
Do I need a movable lift point?
You may often need to reel on/off the cable during the ROV operation. A movable lift point allows you to do it without turning off the power supply and disconnecting the cable. It is much more convenient to operate with a movable lift point, but still possible without it.
Is it necessary to use the flotation module
The flotation module is absolutely required. It makes the vehicle neutral buoyant.
Does ROV GNOM have a system allowed to locate the vehicle position??
Yes, such system is called the "hydroacoustic navigation system" and can be carried by the vehicle.
What is the temperature range of ROV GNOM operation?
The following weather conditions are permissible during the ROV GNOM operations: air temperature –20 +45?C; relative moisture up to 98 %; atmosphere pressure from 84 to 106,7 KPa (630-800 mm Hg). The cable connection between the surface control panel and the vehicle can transmit signals at air temperature –20 +45?C and water temperature –5 +45?C.
I heard about DOUBLE RESCUE SYSTEM. Could you provide more information?
This system has been developed for operations in hard-to-get-at places. Modified ROV Sealion developed by Fisher is used as a carrier for small sized ROV GNOM. The whole system is based on Ethernet technology and may integrate various devices with standard interface. The sonar Miniking is installed on the system.
What is the maximum current velocity allowed during the ROV GNOM operation?
The self speed of GNOM standard and Super GMOM is about 1 – 1.5 m/s. Current velocity below 1 m/s is allowed during the operation of these modifications. Up to 2 m/s current velocity is allowed for modification Super GNOM Pro.
What is the maximum time of underwater operations?
The maximum registered operating time for ROV GNOM in the sea (100 m depth) is 3 days. In aquarium filled with fresh-water ROV GNOM may operate during several months. There are no operating time limitations if you can provide uninterruptible power supply.
What can you recommend for underwater survey of the cable laid underground?
Magnetometric system installed on ROV Super GNOM Pro will allow the vehicle to follow exactly the cable bedding.
How can I plot a geographical position of ROV GNOM?
The hydroacoustic navigation system (TrackLink 1500, Tritech MicronNAV) must be installed on the vehicle to plot coordinates of the vehicle.
What additional equipment is required for video record during survey operations at shallow water depth in absence of the ship with self-contained power supply?
The built-in battery (12V) will supply the ROV for about 1 hour. For longer operations you may use current generator (220V, 50 GHz) of a car battery. Video can be record by digital recorder or video camera or laptop.
Does ROV GNOM have an emergency ascent system in case of cable rupture?
No, ROV GNOM does not have an emergency ascent system. Cable breaking load is about 100 kg. There is no any information about the cases of cable break during the operation.
What shall I do in case of the cable hook?
In case of hook you may move the vehicle back following the cable. The success of such operation depends mainly on pilot's skills.
In what countries ROV GNOM applies?
Only 30% of ROVs GNOM have been sold in RUSSIA. The rest has been sold overseas to various countries such as England, France, Germany, Italy, USA, India, Australia, Middle East countries and Asia.
Have you performed any specific investigations of ROV GNOM operation under conditions of strong current?
The quality of ROV GNOM operations strongly depends on pilot’s skills and experience. In some cases you may use an anchor connected to the ROV’s cable. Permissible current velocity is about 1 m/s.

All you need to know about GNOM ROV.