Linked from
The 17 pages that link to Mean sea level, each with the reason it gives.
Tidal rangeRelated: It provides a reference for placing tidal highs and lows in vertical context.
ElevationRelated: It is a common reference for reporting land elevations.
Sea-level changeRelated: It provides a local baseline for tracking persistent rises and falls.
Height above mean sea levelRelated: It supplies the reference level named in this height measure.