Answer: sealevel

AnswerCrossword Clue
SEALEVEL0, in some measures
SEALEVELSomething on the rise today
SEALEVELRising concern?
SEALEVELIt rises every year
SEALEVELCruising altitude?
SEALEVELWhere the buoys are
SEALEVELElevation standard
SEALEVEL0 on an altimeter
SEALEVELHigh ground is above it
SEALEVELLand formation measuring standard
SEALEVELPart of New Orleans is below it
SEALEVELIt's affected by global warming
SEALEVELDenver is way above it
SEALEVELThe Caspian is just below it
SEALEVELStandard reckoning in elevation
SEALEVELAquatic plane
SEALEVELStandard for measuring heights
SEALEVELStandard for altitudes
SEALEVELStandard for measurement of heights.
SEALEVELStandard measure for height of land.
SEALEVELStandard for height measurements.
SEALEVELAltitudinal reference
SEALEVELDeath Valley is below it
SEALEVELWhat many port cities are at
SEALEVELAverage height of the ocean's water
SEALEVELZero altitude
SEALEVELWhere many geographical measurements begin
SEALEVELAltitude baseline