Does this look familiar?
If you can communicate through voice chat while in this state to your crew, you can get back into the game without quitting.
Ask the crew to vote you to the brig.
Once jailed, you will finally load into the game and be in the brig.
After a bit, they can release you.
If you have issues, like no items/cosmetics, you need to die to reload your character (mermaid travel doesn't fix it).
You will load properly on the ferry and can resume gameplay.
Hopefully this post becomes irrelevant when the days of being stuck loading are in the past.