Plants that grow beside water bodies rely on water to transport their seeds. They usually produce light seeds that float, or the seeds may have fluff to help buoyancy. Seed dispersal through water is known as hydrochory.
Lol I don't know how to answer this question but I think coconuts fall/roll and land into the ocean and then get washed into another shore and grow there. I'm not sure if that helps though, lol. anyway.