The game really misses a lower-tier native sea creature.
I get that the krakens are there to discourage you from going into deep ocean (since you're no longer restricted by technology to go into ocean tiles) but there are too many. Sea dragons on the other hand, are supposed to be a general threat but are too powerful.
The whole thing would work a lot better if krakens were rarer, a bit like siege worms, sea dragons only go in deep oceans to kill off early explorers and something else, something weaker fills the "harass coastal waters" niche.