*cough* Marianas trench *cough* *cough*
No, don’t do it! It will cause a crack in the deep ocean floor which will allow a Megaladon to escape from a sub-ocean and terrorize the oceans, eating blue whales, and people indiscriminately.
:-)
Peach
*cough* laurentian abyssal *cough*
Cc
Marianas trench? That would be my pick too. Find the spot where one plate is being crushed under another and drop the ship there. Let the ship get ground back into the Earth.