From Halopedia, the Halo wiki

Wake-breakers were a class of transport vehicle employed by the Sangheili of the Former Age - the era prior to the foundation of the Covenant empire. Alongside sky-cutters, wave-breakers served as one of the distinct ancestors to the line of civil and domestic transport shuttles that would eventually culminate in the development of the Phantom line of armed military dropships.[1]

Further details on the wave-breaker are unknown, though its naming suggests it may be related to the wave-skimmer - a class of maritime transport employed by modern post-Covenant civilisation on Sanghelios.