The MOBULA 8, groundbreaker

Now in its 6th month, our pilot project to clean up Bali's rivers and calm waters is in full swing. Carried by the MOBULA 8, our first multi-purpose water pollution control boat, it will enable The SeaCleaners to significantly improve its means of combating plastic pollution in the most impacted areas, while preparing the MANTA's future operations. An accelerated learning curve well worth summarizing!

Officially inaugurated on March 20, in the presence of our local partners and the Indonesian government, and in operation since May, The SeaCleaners’ very first MOBULA 8 is fully playing its role of trailblazer for the deployment of the association’s field operations.

Because great stories are built on small steps of observation, evaluation, iteration, improvement and (from time to time!) missteps, our operational team, led by its director Pascal MOUNIER, an expert in international program management, takes a close look at the results obtained by the MOBULA 8, both in its floating waste collection activities, and in its scientific and awareness-raising missions.

The aim? To put in place a rigorous feedback process, before moving on to the phase of scaling up a fleet of “in-solidarity MOBULAs”.

With 3 new boats in the MOBULA range due to be delivered shortly (two new MOBULA 8s and a larger MOBULA 10) and put into service during 2024, the lessons we’ve learned from the pilot project in Bali will enable our teams to significantly increase the effectiveness of our future field operations in Bali… and elsewhere!

MOBULA 8 technology: efficient... with room for improvement

Over the course of the summer, some 30 trips were made to the rivers, canals and mangroves in the Benoa area, the home port of the MOBULA 8 in Denpasar, to test the boat in different vegetation configurations and to take seasonality into account.

With the monsoon season coming to an end in June, this is an ideal time to collect the floating waste that is carried en masse to the Java Sea during the summer by the island’s 372 rivers.

Thanks to its suction system, the boat has demonstrated its ability to collect between 150 and 175 kilos of waste per hour in high-density areas. Around 6 tonnes of waste were thus removed from the water.

Based on this feedback, optimizations will be made to the two future MOBULA 8s, enabling them to increase their performance and collect 200 kilos of waste per hour.

Clean-up operations in the mangroves, which are very numerous in Bali, have also shown that improvements are needed to clean up these ecosystems, which are as essential as they are fragile.

While floating waste is collected without any major problems in these forests of trees growing on the shore or in the water, the same cannot be said for light waste such as plastic bags and plastic sheeting, which sink into the mud or get stuck in the breathing roots of mangroves, becoming entangled deep in the vegetation. But bags are single-use products still used on a massive scale in Indonesia… and thrown away just as massively! They are therefore found in very large quantities in mangroves.

Teams from our integrated engineering office MANTA INNOVATION and the boat builder EFINOR Sea Cleaner are working together to take this data into account and propose solutions for new means of collection to address this problem.

On the clean-up front, the MOBULA 8 has twice been used very effectively to collect hydrocarbons in Benoa Bay, following deliberate pollution from land.


Developing complementary collection solutions

Various aquatic clean-up operations carried out with local players have also shown us the need to develop other solutions that will complement MOBULA, such as universal collection mats and concentrator nets.

These low tech systems, which are affordable and can be manufactured locally, will increase the collection efficiency of the boats.

The MANTA INNOVATION teams are already hard at work designing them, and we look forward to presenting them to you very soon, when the test phases begin.

Understanding waste dynamics for better action

The majority of MOBULA 8’s summer outings were aimed at a mission other than just collecting garbage: understanding the dynamics of plastic waste in the key Benoa area, where numerous rivers flow into the Java Sea.

An impressive piece of scientific work was carried out in collaboration with our partner, the local University of Udayana (see our article on the scientific aspects of MOBULA 8).

Density of the slicks as a function of seasonal variations, characterization of the plastics contained in the slicks, analysis of the drift of floating waste and of the factors causing areas of accumulation: this work enables us to understand where the most important deposits are located and how they are formed.

In addition to mangroves as waste retention zones, areas of high human activity, such as markets, harbours and rivers with densely populated banks, are logically major sources of waste. This empirical observation corroborates the recent study published by Prof. Denise Hardesty, a member of The SeaCleaners International Scientific Advisory Board.

This scientific analysis has a triple merit:

  • It shows the extent to which raising community awareness is key to cutting off the plastic waste tap at source. Ketut SUDARWATA, Project Manager of The SeaCleaners on site, has carried out dozens of awareness-raising operations in the area, often in partnership with other Balinese environmental associations, and with the Indonesian Navy, which is officially responsible for protecting the coastline. These numerous exchanges help strengthen our ties with the community of public and civil society players working to combat pollution in Indonesia. Since March 2023, several hundred people have been sensitized in Bali, in the course of around ten actions.
  • This will also enable us to precisely identify the future intervention zones of the MOBULA 8 and those of the larger, wider MOBULA 10, which will be able to collect waste from rivers with higher flow rates and off the coast (up to 20 miles). Several intervention zones have been preidentified in Bali and on other islands in the Indonesian archipelago. A field evaluation, prior to the commissioning of MOBULA 10, will take place in November this year. It is hoped that MOBULA 10 will arrive in Indonesia in early 2024.
  • Last, it will help to determine the MANTA’s future routes, to optimize its efficiency in collecting floating macro-waste, while minimizing its journey times, environmental footprint and operating costs. The trust-based working relationships established with local authorities as part of the MOBULA 8 pilot project in Bali will also be invaluable in accelerating the steps required for the operational activation of the future giant of the seas.

And in the short term?

Today, it is estimated that Asia accounts for no less than 81% of the global input of plastic into the oceans.

Two optimized MOBULA 8s will therefore be deployed in 2024 in another ASEAN country. Contacts with the authorities are underway, and several exploratory visits are scheduled.

See our article on the MOBULA in-solidarity fleet

A huge THANK YOU to all those involved in implementing and analyzing the progress of the pilot project:

  • Our field team, Captain Linda and Pak Herman who operate the MOBULA 8,
  • Antoine Iché, Ketut Sudarwata and Alice Darondeau steering the project,
  • Elise d’Epenoux, in daily contact with our institutional partners and public authorities,
  • Fiona Yap of Bali Marine Service for her indispensable logistical support,
  • Our scientific manager Gwenaële Coat, who oversees the research component with our local academic partners,
  • Our Awareness Manager Stéphanie Poey for the essential educational work we’re doing with local communities!