Why satellites cannot simply reveal submarines

Could satellite cameras and enough computing power detect submarines from space?

Not reliably without a far richer, continuously updated oceanographic baseline than governments currently possess.

Computing power addresses only part of the detection problem. Analysts first need dense observations of currents, temperature, density, weather, and other ocean conditions against which a suspected submarine trace can be compared. Governments began taking the idea seriously decades ago but had sampled only a fraction of the ocean, and post-Cold War cuts removed some of the survey ships gathering the required baseline. The effects of a deeply submerged boat may be extremely small compared with natural movement in the water. Because currents and density patterns continually change, including with climate shifts, the reference model would also require permanent updating rather than a one-time survey.