Long story short: a cultural tradition of this (late medieval/early renaissance-ish) civilization is to put their deceased in a casket/boat/raft, and float them out into the ocean. Their belief is that they're sending their loved ones off to the afterlife, and at some point they float into the supernatural dimension where they wake up and join the afterlife. My idea is something along the lines of they get pulled into a current that eventually drops them off in a small cove or something far away. However, there's some things that still need develop. The cove needs to be well hidden, both from sailors along the coast and anyone who lives on the land. It should also securely collect nearly all the things that float downstream, because it wouldn't do to have random bodies floating around the ocean. So the question is, what is this "cove" like? How does the current work and how strong does it need to be? What material should the bodies be placed in? How plausible is this concept?
This idea is pretty flexible. There's not much geography planned for this region yet, and I can probably work with whatever you guys can suggest. Also if the cove idea doesn't seem plausible, I'm open to any other explanations (maybe they get sucked underwater and lie on the ocean floor?). Pretty much any input helps.