I do not believe that all of the shaved off marine growth is captured, not in the sea with currents and with the machinery involved. Minute particles which are invasive to the locality could endanger the area around.
regards

Emmanuel.L, if you watched the videos as recommended you would have seen all the growth/paint etc. is captured and removed from the water. Used to produce green electricity.
At Southampton process is completed while ships are alongside berth within their normal turn round time.
Can achieve in excess of 25% fuel saving so cost efficient and less engine pollution.

Presumably this underwater cleaning is done in harbours and sheltered bays and rivers, so what happens to the growth shaved off plus possible paint? Is it allowed to contaminate the environment around? Much of this marine growth is accumulated from far oceans which are invasive to the local marine environment.
Ship owners may profit from this "cleaning" service.But is it worth the it for the countries seas it is undertaken in?
regards
Emmanuel.L.(Malta)

Robotic Underwater hull cleaning.
See the link at end ...system employed in Southampton and soon in Rotterdam.
First video is relevant approx half way through. Next videos shows system and savings to ships efficiency and climate.
https://www.facebook.com/ecosubsea/

Hi again MattyBoy, a local company have developed their own, patented system. Divers and machines do the job.
If you take a look at this link to the CLYDE (an interesting and fine old vessel) I have included some additional links there to the company 'Marine Service'.

I have just noticed a UK flag at the top of those pages for their English language versions.

They have a lucrative business and seem to be always busy.

Regards, Rick

Is there a special technique employed for the underwater hull cleaning ?