Measuring current or past sea-level change (SLC) is inherently relative, i.e., we compare the change to a recent strandline or the last recorded highstand or lowstand in the stratigraphic record. Modern satellites equipped with precision altimeters can determine sea and land surface elevations with respect to Earth's center or a theoretical spheroid, achieving an accuracy of ±3 cm. However, when we venture into the geological past, we lose the luxury of an independent measuring stick. Instead, we rely on present-day mean sea level as a practical reference point for estimating ancient sea surface heights. Yet, we must remain aware that such comparisons, constrained by our present-day, shore-bound perspective, offer only limited qualitative insights into the actual shifting contours of Earth's oceanic past.