It is always a pleasure for PARALENZ to be part of research expeditions, science explorations and of course, organizations that have the aim to clean and make a better future for our big blue. The Hecataeus Dive Project is part of that segment. As the purpose of the team is to research and gather data about the Hecataeus seamount, located in the marine territory of Cyprus.
In the previous blog post, we made an introduction to this project, giving a general overview of the scope of the project. Now we will go deeper into the testing phase, and see how the team is moving along.
For initial research and dive planning, the Oceanography Centre deployed a glider to the Hecataeus Seamount. Gliders are autonomous underwater vehicles carrying an array of sensors to collect seawater data. They are controlled via satellite to a pilot on shore with pc.
Gliders are pre-programmed and have a dive operation of 7-8 hours with a duration of several months. During surfacing, data exchange takes place via satellite. They can dive to depths of -1000m some models to -6000m. For the Hecataeus Dive Project, they collected current and temperature data. The findings were a maximum current of 0.5kn and a minimum sea water temperature of 15C at the Hecataeus Seamount.
The co-operation of the Oceanography Center – University of Cyprus involves the section of marine biology.
Besides shallow sea bottom sampling for microorganisms and video and photo data, they will deploy a rosette.
A rosette consists of a frame holding an array of bottles and a CTD sampler.
The bottles collect seawater at different depths for later analysis and are controlled remotely.
The CTD is a sensor array to collect current, temperature, and depth in relation to the water samples of the bottles. The whole system weighs about 150kgs.
Remotely operated underwater vehicle
The ROV was initially used on the first visit to the Hecataeus Seamount. However, we lost control and signal which was caused by the abundance of sharks. We also use the ROV during the manned dives for pre-dive checks (safety swims), diver safety monitoring, video capture and live dive transmission purposes.
We will use three different models. One for the site investigation and training, one for the stress tests in Canada and one for the real dive. The ROV’s are sponsored by Brasal Marine and Huntleys Diving.
In January 2018 we conducted a stress test dive in Nova Scotia, Canada to simulate shallow decompression stop hypothermia and psychology. The water temperature was 2C and we managed 2.5 hrs submersion. For this test, we incorporated a “Cyborg” pill which was ingested to measure core temperatures in connection with heart rate. The pill was sponsored by HQinc. from the USA and in part developed by NASA. It consists of a battery, temperature sensor, transmitter and transmits live core temperatures to a recorder which data is later analyzed on the computer.
The dive equipment was sponsored by Huntleys Sub Aqua Construction including an ROV. This ROV was also used to test live dive streaming and we were able to communicate in picture and audio from underwater to individuals around the world in real time.
At the end of the dive, due to the cold, I had impairment on the jaws with difficulties talking, restricted fine finger and hand movement and loss of feeling in one leg resulting incapability to walk for a limited time.
For reasons of safety, we used surface supply equipment with communications, the ROV, 2 dive tenders, 1 dive supervisor, a safety diver who is an offshore sea survival instructor and paramedic, a certified nurse and a heart doctor.
We also tested different kinds of layering, materials and different kind of heat packaging. The pre-dive preps included a 2-week specialized diet of carbs and seaweed. For the simulation, we opted for a depth of -3m (buoyancy) and a severe restriction of movement (limited to 2m in a 3D environment).
The dive equipment consists of a CCR and bailout system. All of it was for most of the part configured for just this dive with a lot of custom made parts. As we have to some work upon reaching the bottom (sampling) we focused on equipment safety and simplicity of use. As such we incorporated the bailout system into the CCR system to minimize carry load but each gas and supply tank can be used independently open circuit without manually switching regulators. For this reason, a Draeger full face mask was chosen and the connections were custom made in Germany. The rebreather and bailout system is connected to the mask via 3 quick connect ports and can supply all the necessary gases.
The bailout system consists of 4 x 20-liter tanks with 4 different breathing gases totaling 17600 free liters. In addition, there are 2 independent inflation systems supplied by 2 x 5-liter tanks.
The total dry weight of all the equipment is about 150 kgs which include the sampling tools, lights, etc… For post diving, a system of different gases to counter isobaric counter diffusion is set up.
The downline system is the only connection and reference to and for the diver. The diver is at all times connected to the downline via a 3m long safety umbilical throughout the dive. This is also partly due for a possible diver recovery scenario in case of an emergency.
The downline is marked in 10m increments for reference used by the diver and surface support. Topside the downline is supported by two individual and separated buoys plus a small pick up buoy connected with a line.
On the bottom the downline is weighted by a metal clump weight of 65kgs. 2 meters above the clump weight is a rubber hammer which might be used to assist when using the core sampler to drive it into the ground.
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