ROV dives for dummies!

With the collaboration of the ROV Holland 1, the scientific expedition TOSCA, the Research Vessel Celtic Explorer, from the Irish Marine Institute ( , and some notes from Dr. Katleen Robert (Memorial University of Newfoundland, Canada). 

Everything you always wanted to know – from A to Z about how to succeed a ROV (remotely operated vehicle) dive.

1)     Go to sea with a bunch of very talented ROV pilots: 6 is a minimum number (3 for each 12 hours shift).


2)      Set up the OFOP (ocean floor observation program) software on the computer to be able to record in real time any special features, biological or geological  (such as fish, scarp, boulder field, shimmering water, soft sediment, anemone garden, etc.).

A biologist, a geologist and a map wizard discuss locations (Katleen, Bramley and Oisin). © Adeline Dutrieux.

3)   Plan the dive according to your purpose and allowed time. Set up the planned track on the ROV monitors to help scientists and ROV pilots to follow it. Technically a dive could last forever. But ideally, a dive will last about 12 to 24h or until it had achieved its objectives.

4)      Start the dive. Watch the blue becoming darker and darker.

Start of a ROV dive. © Evi Nomikou.

5)    Two scientists join three ROV pilots in the ROV container, located on the back deck, close to the immersion platform of the ROV. Together they will watch the HD camera located on the front of the ROV and discuss the appropriate moves to make.

Isobel and Patrick (in the back) are in the ROV container, their eyes focused on the HD camera in front of them, the OFOP map and the planned track. © Maria Judge.

All information we need in less than 2 meters square, and in front of our eyes: HD camera video, HD photography, positions of the ship and ROV with coordinates, time, and location on the geological map with the track line. © Adeline Dutrieux.

6)      One scientist is in charge of the camera joystick and capturing as many photographs as she/he can with a stills camera mounted on the ROV frame. Remember to zoom in close to the seafloor to allow animal species counting!

A coral and sponge on the seafloor, illuminated by an ROV light.
Beautiful coral and sponges on the top of a ridge, picture taken by the HD camera.


7)      The other scientist is in charge of recording and clicking as much as she/he can on the OFOP (ocean floor observation program) software along the track.

4 people smiling and holding a bag of crisps whilst watching a tv screen
While two scientists are in the ROV Container located on the back deck, the others, on shift, watched the broadcast camera in the Dry Lab, sometimes, with crisps and music. A very talented ROV pilot slowly grabs a rock from the seabed with a manipulator arm. © Elisa Klein.


8)      Together identify locations for sampling and ask to stop the ROV for rock or biology sampling. Sometimes we cleaned the seabed of glass bottles.

A robot arm collecting a green bottle from the seafloor.
Grabbing a green glass bottle, next to a squat lobster. Fortunately, we didn’t meet many of them.  © ROV Holland 1.

9)     See a crinoid, or a skate egg. Ask for “grabbing” or “sluuuuurping” the specimen (main biology goals during our mission). From the biology side, to get an idea of environmental conditions, we can look at the bathymetry (the shape of the seabed) and examine whether there are relationships between where species occur and different terrain characteristics (e.g. depth, slope, direction of slope, roughness of the terrain).

10)    On the geology side, look at the faults, scarps, fractures, change of sediment lithology, or boulders fields. Ask one of the ROV pilots to kindly sample some rocks at specified locations. He/She gently manipulates the arm and grabs with dexterity the rock. Sometimes that rock is bigger than expected – we call it “iceberg”!

11)    Decide which bucket or drawer compartment to drop the sample in. Very often, each compartment ends up with 2 to 5 samples. Remember to write down the sample location, the event number (sequence in which it’s collected), with their precise location and description so that we can identify them when they are brought on deck.

12)    Once in a while, when the terrain allows it, create a photo-mosaic. It consists of going from side to side on a steep scarp, and then moving up a level and repeating the process to obtain a full and very detailed surface of the scarp (like a close-up panorama).

13)    Every two hours, another buddy pair comes to take the lead. Fresh minds start over.

14)    A dive can continue as long as the weather stays fine. At the end of it, retrieve the ROV on deck.

A stalk yellow crinoid. © ROV Holland 1.
The arm gently detaches (at the top) the stalk yellow crinoid from the seafloor. © ROV Holland 1.

15)    On deck, once the ROV is secured by the technicians, start unloading the samples. It can be a puzzle with sometimes vague description (“black large rock”) and blurred pictures to identify which rock belongs to which event so be careful to provide better descriptions in the next dive. Similarly, collect the biological samples. Label everything!

Maria and Arne are unloading the biology and rock samples from the ROV on a night shift. © Maria Judge.

16)  Once all rocks have been identified to each event/sampling location, brush them from their saline and encrusted life cover.

Brushing rocks – they stink! © Evi Nomikou.

17)   Photograph the rocks with a correct label and measure the dimensions.


Steve, Elisa, Bramley and Adeline are describing the rocks.  ©  Bramley Murton.

Pat is ready to unload the biological samples. Crinoids and skate eggs were our special dishes on this expedition.

Oisin, Aggie and Katleen are taking care of the push cores.

18)   Chop a bit of rock and describe their textural and mineralogical features.

19)   Give a provisional name.

20)   Finally pack them in their bag. Make sure the label is legible and will stay. They will be described later in full details in labs by petrologists.

Concerning the biology, scientists will look at the morphology in greater detail, and if possible, carry out molecular analysis (e.g. DNA, RNA).  Many deep-sea species are still unknown, so maybe one of the sample we collected will turn out to be a new species!

21)   Job done! Have a cuppa.


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