First of all, I doubt that making the ship "the sturdiest to ever sail the Twin Dragon Sea" (cool name by the way) is useful to the story if it's going to get destroyed anyway. Maybe, you should include some rival ships (pirates, marines, etc.) to prove just how superior The Resilient is in comparison to the rest, and then have it destroyed to show how dangerous (hard) the rest of the journey (game) is.
Since the MC's main motivation seems to be fame and glory for getting a legendary treasure, and these wishes could be attributed to whoever's heard of the island, it would make sense for him not to be the first to wash ashore, and instead have bandits or something like that who also came to the island by accident to fight the MC in land.
Also, it seems to me that the main attributes of the MC are that he is very perseverant and had the sturdiest ship ever, but if you're taking away the ship at the beginning, then maybe give the ship something, like a magical engine of sorts, that could be fundamental to surviving in the jungle (because it creates some sort of barrier, shoots fire, or something else). That could give the player the objective of exploring the jungle to seek such important item, that gave him the chance in the first place of getting the treasure. It makes no sense to have a ship that can survive anything, if then you can't use it anymore and you lose that edge, if you can plan for the sea, you should be able to plan for land. Maybe the plan was to carry this special item in the ship as protection, and unload it on land to advance.
I'm not really all that good of a writer, but these are just some ideas I had after reading about your game.