The impression of the dream is important for the waves. If for example, you dream of waves in a calm or peaceful ocean, then there is no problem. And it's even the opposite, because it means that your difficulties are now gone. Dreaming of wave at dusk are the most dangerous. If you dream of hearing a wave, but don't see it, then it means punishments for sins that you have forgotten.
Dreaming waves in Islam while on a boat indicates that many people will be affected by the misfortunes. And you have to interpret the dream according to what happens after the wave. So, if you fall into the water after being hit by a wave in the dream, then your misfortunes will put you down (for example, a job loss or bankruptcy). However, this is rare, as the waves mostly indicate sins that must be repented of.