(HOUDINI) RBD object suddenly keeps sinking in fliptank? help please!

i created a simulation of a ship floating oon water using this tutorial [https://www.youtube.com/watch?v=ofPJbn03thc](https://www.youtube.com/watch?v=ofPJbn03thc) and it worked well.

however i then added a big rock as a static object collidor around the water, and while this worked well too, now my ship suddenly keeps sinking. i can't figure out why, i changed the density and the feedback scale but neither of that did anything.

is anyone able to figure out what went wrong here or would be able to help me fix it?

here's my file and the ship i used:

[https://www.dropbox.com/scl/fo/bhr9134hu1hoq6v650u6d/h?rlkey=s9wz1u5171a6iy3mb7e98bhlt&dl=0](https://www.dropbox.com/scl/fo/bhr9134hu1hoq6v650u6d/h?rlkey=s9wz1u5171a6iy3mb7e98bhlt&dl=0)

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it's for a university project so it's a bit urgent, if i dont find any solution, i'll just hand it in without the rocks though.