composed primarily of
ocean
https://en.wikipedia.org/wiki/Ocean
FTT:1019
EcoLexicon:ocean
envoPolar
FTT:943
ocean region
LTER:695
Geonames:H.OCN
A marine water body which is constitutes the majority of an astronomical body's hydrosphere.
envoMarine
TGN:21102
SWEETRealm:Ocean
marine water body
sea water
saline water body