Yeah, this seems really smart to me, as long as you can avoid the obvious problems with it being submerged in fucking corrosive as shit saltwater. Makes way more sense than using A/C since the ocean is a giant heatsink.
I am guessing OP is worried about either these things being a driver of why the oceans are heating up (not the blanket of CO2 around Earth in the atmosphere from decades of fossil fuel powered binging) or the ocean being too hot to effectively cool these things, which also doesn’t seem plausible outside of very specific locations/depths.
I think this would be better than doing it on land, however I also think that it’ll be costly and need to be over-engineered to survive the environment and not worth it in the end (as MS has apparently come to the same determination).