Early Primitive Elvish
sara
root. *saw
sara Speculative
root. *surf
þara Reconstructed
root. *saw
þolo
root. *surf
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
A hypothetical root explaining various related words in Gnomish Lexicon of the 1910s such as G. saros “surf, sea” and G. sôr “wave” (GL/67). There are no signs of this root being used this way in Tolkien’s later writing.