I'm not sure that's what you intended (2.2mm - did you mean 2.2m ?), but people wouldn't even notice a 2.2 millimeter difference in their coffee cups, much less

I'm not sure that's what you intended (2.2mm - did you mean 2.2m ?), but people wouldn't even notice a 2.2 millimeter difference in their coffee cups, much less in oceans. Even if you live right next to an ocean, or a river, or even run a hydro power plant, a 2.2mm difference in that water level is literally smaller than you can measure even if you really tried to - the natural random fluctuations of "your" water level (e.g. the effect of current, or small waves or ripples even in very low wind) are far greater than that.