Fire as base is needed. To make hydraulic or other tech, you need metal, and to work with metal, you need fire to melt and form it. An aquatic species can evolve to an advanced intelligence, but it can't evolved to an advanced tecnology. Dolphinse have a great intelligence, not far from the humans, but they never can be a tecnologic advanced species, they don't have even hands to manipulate tools. They use tools in a basic way, they even use old fishernets they found on the ground to hunt fishes (observed in the Mediterraneo). But manufactoring it is other thing.