They’re talking about 100 - 300’ depth. So they’re likely talking about the thermocline. If the thermocline is ‘trapping heat’ relative to the oceanic temperature it means sea surface temperatures are dropping as thermoclines usually represent latent heat from the prior summer. They may be stating facts however they are mis-representing them as global warming.
If the oceans in any way are warming up, then the water would expand and the water level would grow significantly. This higher water level is not happening, though.
So much for that theory.
Indeed. The oceans are a physical system and cannot by some will of Gaiea “hide” heat.
Exasperating.