mL, L, cm3, m3 are all SI units that can be used to measure the volume of water.
You would use the metric unit "liters" to measure the capacity of a hot water tank.
Liters (L) is the best metric unit to measure the amount of water in a pool as it provides a convenient measurement for large volumes of liquid.
The metric unit commonly used to measure the depth of water in a bath is centimeters (cm) or meters (m).
Meters
Metres.
centimetre.
grams
litres
Centimetres
the metric system
The metric unit of length is the 'meter'.
Pints