You would like to create a toposurface and label the contours with sea level elevations.
Issue: By default a project starts with the survey point and the project base point at 0, so elevations used when creating a toposurface are relative to this 0 point.
Solution: By adjusting the position of the project base point and the survey point you can work with the project using sea level elevations.
Video: Use Sea Level Elevations for a Toposurface