This is the 14914th most frequent Russian word.
подводные
"Подводные" means "underwater."
Here, 'подводные' refers metaphorically to hidden or underlying threats, much like those beneath water.
Книга исследует подводные опасности экономики.
The book explores the underlying dangers of the economy.
In this sentence, 'подводные' literally refers to something occurring below the surface of the water, specifically currents in this case.
Мы наблюдали подводные течения во время дайвинга.
We observed underwater currents during diving.
'Подводные' in this context is used metaphorically to imply hidden or root causes, similar to how certain phenomena are hidden beneath the water.