Variation of concentration of chlorophyll-a, an indicator of plankton, for May 2025
Gordon embraces some typical late spring snotty viz
a feedstock for larger marine species.
Ever present in our seas, their abundance varies through the year, often peaking in late spring as natural variations in ocean currents bring more nutrients to the surface, and longer days mean an increase in available sunlight for photosynthesis, causing a natural explosion of numbers which is often exacerbated by agricultural fertilizer runoff. Although individual plankton are microscopic, they clump together by the billion to form strands of stringy snot that have become an all-toofamiliar feature of my safety stops in the early diving season.
Seeing the future
So far so good, but what are the practical applications of this data?
Tech founder and freediver Dima Karamshuk has been tackling this very problem. Launched in 2024, his Marla app uses AI algorithms trained on vast meteorological and satellite datasets, supplemented with real-time diver reports, to predict visibility.“ When we started Marla, many of our diver friends were sceptical,” says Dima.“ Luckily, we finally have the technology to crunch through millions of data points and find patterns too complex to be derived by even an experienced human observer.”
Make no mistake, this is a ferociously difficult technical challenge; however, Dima’ s tech industry background, combined with years of research and a sprinkling of innovation funding, are beginning to bear fruit. The current algorithm boasts nearly 60 % accuracy, showing huge progress towards the goal of taking the guesswork out of site selection. And as the community of users grows and more visibility reports are logged,
CREDIT: DIMA KARAMSHUK
The Marla app provides visibility forecasts around the UK and abroad
the predictions will further improve – a genuine win for the diving community.
For Dima though, the project is about more than just numbers; it’ s about accessibility.“ The undersea world is so exciting and under-explored that diving sometimes feels like a space voyage to another planet.” he explains“ We hope that our technology can be a small step towards bridging that gap of understanding and appreciation of the ocean. And hopefully get more people in the UK and around the world to explore the undersea world first-hand.”
Moving forward
By leveraging publicly available satellite data we have shown how water visibility is a complex interaction of shifting sedimentary and seasonal plankton. Of course, satellites cannot capture
every variable; from thermoclines and haloclines, to turbulent mixing and marine‘ snow’, there are too many to cover in a single article.
However, our dive into the data has given us an fascinating foundation for quantifying our understanding in broad terms. As technology moves relentlessly forward, and innovators such as Marla bring further advances in predictive modelling, it’ s an exciting time for those who want to peer deeper into the mechanics of our seas. We are moving towards a future where we can truly understand, and predict, the visibility variations that affect our marine explorations. �
■ This article has been researched using EU Copernicus Marine Service Information – doi. org / 10.48670 / moi-00286
Gordon and Emma, both BSAC members, are the authors of Snorkelling Britain
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