You can't interact with your initial "dead" boat until you save up 2,000 currency to purchase an iron boat from the boat seller.
Crafting this key unlocks the "The Key to Your Past" achievement and is widely speculated to be the only way to reveal the player's true origins on the secret sixth island. 🏝️ Hidden Island & Secret Characters Spirit of the Island v1.0.5.0.rar
On Silver Lake island, there is a waterfall you can actually walk behind to discover hidden areas. You can't interact with your initial "dead" boat