Answer:
It is a ship's hull
Step-by-step explanation:
The riddle is incomplete since is missing a few words at the beginning, here is the complete riddle:
"Often I must war against the wave and fight against the wind; I contend against them combined, when, buried by the billows, I go to seek the earth; my native land is strange to me. If I grow motionless I am mighty in the conflict; if I succeed not in that they are stronger than I, and straightaway with rending they put me to rout; they wish to carry off what I must keep safe. I foil them in that if my tail endures and if the stones are able to hold fast against me in my strength. Ask what is my name."
The ship's hull get in touch with all the nature's elements as the ship is sailing, it has to be strong to endure any kind of weather and even unexpected disasters, it also storages the things that the crew carries to other lands, all of these shows that the riddle talks about the ship's hull.