I'm honestly finding it extremely difficult to find details about this particular method of travel. As of right now this is simply a hypothethical as I'm not going to move the Netherlands yet, but it was interesting - I had heard from a friend that some boats go on so-called "relocation" trips long-distance, even across the Atlantic, such as Miami-Amsterdam. But whenever I google these terms - "relocation trip Miami-Amsterdam", "Miami-Amsterdam cruise ships", "cruise ship florida to netherlands", I'm inundated with a whole bunch of information from various unreliable sources and no real way to know what's real.
What's the correct way to approach researching cruise ships? What are the reliable sources of information? Where can they actually be booked? A lot of sources assume you're travelling for pleasure rather than one-way to actually reach a destination, so finding things catering to that niche seems even more difficult.