Torpedoes and submarines were long evolutions before they looked revolutionary

Were torpedoes and submarines revolutions in naval warfare or evolutionary developments?

Mostly evolutionary: torpedoes extended mines and ramming, and submarines matured over decades, even though their eventual ability to attack from underwater had revolutionary consequences.

The torpedo can be understood as an evolution from the mine and the ram: instead of driving the ship itself into an enemy hull, the attacker sends a weapon that reaches the hull and opens it to the sea. Submarines introduced the genuinely new ability to conduct sustained operations underwater, but that capability did not appear overnight. Their transition from experiments to useful fleet weapons unfolded across many decades and was visible to contemporaries throughout the process. Their eventual effect was revolutionary, while their development was evolutionary. Many supposed technological revolutions mark the moment when outsiders notice a long chain of engineering advances already familiar within the field.