SeaGuernseyLatest update August 26, 2019 Started on October 19, 2018
The Bailiwick of Guernsey is a community of small islands located in the Bay of St Malo, in the English Channel.
The occupants and visitors of this archipelago of small islands enjoy this coastal environment, with beautiful beaches and challenging sailing, but very few are aware of the vast range of landscapes and diverse environments that lie below the surface of the surrounding ocean. The seas of the Bailiwick of Guernsey include a multitude of underwater reefs, sandbanks, historic shipwrecks, islets, ferocious currents, and a tidal range of up to 32 feet.
A significant proportion of of the seabed in this area is between 130 feet and 230 feet deep, beyond the reach of most recreational divers, and therefore has great potential for exploration.
We have been learning how to ‘fly’ our Trident ROV, and overcoming the various challenges of our local waters. Whilst we are by no means experts, and every trip out is a learning experience, we are now fairly comfortable using it to explore our waters. And what an amazing tool the Trident ROV is. We have already made some interesting observations, but more of that in another post.
We have obtained a 100m meter tether for our Trident ROV, so now have the capability to explore the full range of habitats around our coast.
For anyone using, or thinking of getting, a Trident ROV we thought we’d share some of our experiences with familiarising ourselves with the Trident, and some of the challenges and solutions we encountered along the way.
Having initially become familiar with the controls and operation of the Trident from the shore in a seawater pool, without the complications of depth, wind, or tidal currents, we then headed out on a boat. We found that operating in fairly shallow water (down to approximately 20 meters) and with no tide, was relatively simple and easy to achieve ‘out the box’. Operating at deeper depths in our difficult waters initially presented a few challenges:
• Tether drag: Because an ROV operating in mid water doesn’t have purchase on anything it takes very little force to change its pitch or yaw. Any pull on the tether can therefore make it difficult to manoeuvre the ROV. We initially found this an issue when operating at depths beyond about 30m. We found a solution is to attach a weight to the tether a short distance above the ROV to absorb any drag.
• Currents / wind: Operating form a boat which is moving differently to the water column, due to wind or currents, is very problematical because the tether quickly becomes taught and the ROV cannot be manoeuvred. The obvious solution is to only operate at slack water and when there is very little wind, although this can be quite a challenge in locations with strong tidal currents and only short windows of slack water, that are also often windy. Wind drift can be overcome by anchoring the boat, but this only helps when there is little or no tidal current. We experimented with making a harness for the ROV enabling the tether to be attached to the front of the vehicle. This allowed us to tow the ROV behind a drifting boat, in a forward facing orientation, and use the vertical thruster to achieve some depth control.
• Lighting: The built in lights on the ROV are bright and the camera does a good job of working in low light, however when operating beyond the reach of natural light they can only illuminate items relatively close to the vehicle. To overcome this we added an external light source. To attach the light to the ROV body we experimented with a few customs 3d printed brackets, but eventually settled on a quick release action camera fitting.
Operating from a drifting boat carries with it the ever-present risk of snagging on the seabed. If using a weight to reduce tether drag it is therefore important to ensure the weight is attached to the tether using low breaking strain line, so in the event of the weight snagging it can break off. This happened to us once, and gave us a scary couple of minutes before the weight broke away and we were able to recover the ROV.
We are very excited to have received our Trident ROV.
To familiarise ourselves with the vehicle we took it for a test dive in some outdoor seawater swimming pools.
First impressions are really good. The vehicle was easy to setup and deploy, and the image quality good. Having never previously piloted an underwater vehicle it took a short while to get a feel for the controls, but after only half an hour of ‘flying’ the trident I was comfortably navigating the pool.
We are using the standard 25m tether, but will soon be changing to a 100m tether which will enable us to begin deep dives from the boat. In the meantime we will continue practicing our piloting skills and familiarising ourselves with the kit.
SEE Initiative / Trident ROV
We have always been mindful of the limitations associated with undertaking ‘blind’ soundings with an action camera, which is why when we heard of a possible opportunity to use an underwater drone we were extremely interested. The ability to remotely control an underwater camera, and view a live video feed, would be a complete game changer for us.
The Science Exploration Education Initiative (SEE Initiative) is an initiative making grant funded Open ROV Trident underwater drones available to citizen scientists, educators, non-profits, researchers and students to monitor and protect marine environments.
Needless to say we immediately started the grant application process, with barely contained excitement for the massive potential of such a vehicle. The manoeuvrability, and live video feed, of a Trident ROV could enable us to navigate and explore more complex seabed structures, and identify and investigate subjects of interest. This precision could be hugely enabling.
Recently we received the very exciting news that our application was successful and we will be receiving a Trident ROV. Our previous barely contained excitement is no longer contained!
We would like to thank all at the SEE Initiative and their sponsors, Open ROV, and all of you who support us by following our expedition. The use of a Trident ROV will massively enhance our project.
What a fantastic way to end the year, and how exciting 2019 is going to be :0)
A quick update from us.
We are still waiting for a more settled period of weather so we can get back out on, and in, the sea.
It is usual at this time of year for our region to be battered by a succession of North Atlantic low-pressure systems, and this year is no exception.
This weekend we have severe gale force 9 winds (47-54mph) with gusts to 60mph, and 22 foot waves. Living on an island this means ferries are cancelled, and some coast roads are strewn with sand and seaweed.
Whilst not boating weather, from the safety of land it is invigorating to experience the raw elemental force of a storm, and a humbling reminder as to the power of the sea.
We have been reviewing footage from the equipment test drops, and even whilst just briefly testing the rig we saw a number of fish species, including a small-spotted catshark (Scyliorhinus canicula), common dragonet (Callionymus lyra), red gurnard (Chelidonichthys cuculus), lesser sandeel (Ammodytes tobianus) and the charismatic little fish in the photograph below, a Butterfly Blenny (Blennius ocellaris) (can you spot it? centre left with an eyespot on its dorsal fin.)
We are very pleased by the variety of species seen in one brief test drop, and especially the little Butterfly Blenny. This species is rarely recorded in this region, possibly because it isn't targeted by recreational or commercial fisheries, or because it lives in areas and depths less accessible to recreational divers, and therefore isn't often seen.
It is this prospect of exploring areas not previously visited, where our knowledge is limited to what has been fished out the sea, which really fills us with excitement. If we can find a relatively unrecorded species on one test drop, who knows what is waiting out there to be discovered and better understood.
Also carried out a test drop into a deeper area, where the depth was approximately 40 meters (130 feet).
Again a choppy force 5 wind and moderate sea, so still not ideal for imaging, but interesting to glimpse the variety of encrusting animal life on the deeper, less mobile, substrate.
During a slight break in the weather we managed to get out and test the rig for an hour, interested in how the vane would function.
Lowered the camera down to the top of a nearby sandbank, in approximately 15 meters (50 feet) of water.
The wind was force 5, so not exactly ideal conditions for imaging given the amount the boat (and therefore the camera) was rising and falling on the waves, but the vane kept the camera pointing forwards in the tide and whilst slowly trolling.
We have made a few changes to our camera rig, but are still waiting for a gap in the weather to continue testing.
After days of rough and windy weather we now have very thick fog, with the wind due to return again shortly. Whilst not conducive to boating, there is something very atmospheric about these types of weather, which alternately prevent sea or air travel to our islands.
These conditions are not unusual for autumn in the NE Atlantic, and we are hopeful of some settled weather again before the end of this year.
Welcome to our expedition. We hope to share some of our adventures as we explore the marine environment surrounding our home islands.
We are citizen explorers, who have a passion for the seas we have grown up and live by. Please bear with us as we learn and overcome the various challenges of exploring the underwater environment.
So, here we go....
We have started by re-purposing a fishing down rigger, so we can lower an action camera to the seabed.
Our first attempt was in 30 meters of water, however on this occasion due to weather conditions there wasn't sufficient light at that depth to record useful images. We have therefore now attached a light source to the camera, in the hope of providing sufficient illumination.
We are now awaiting a gap in the current stormy weather so we can trial this setup at sea. We have tested it from our marina mooring, and whilst it worked ok, the marina seabed wasn't especially exciting.
Fingers crossed for better weather soon.
The intention of this project is, through he use of underwater imaging and social media, to raise local awareness and appreciation as to the variety of life and landscapes in the marine ecosystem on our doorstep, and the impacts we as humans have on this environment.
“People protect what they love” - Jacques Yves Cousteau
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