Last time I googled this I found it was quite expensive, basically cruise-level per-night prices, at least in my area. Perhaps if you contact the shipping companies directly you can arrange something cheaper.
I could see them considering a risk factor into that pricing. What "normal" person would look to travel this way? Someone with something to hide perhaps? Someone hoping to skirt some of the more rigorous screening of other travel options, specifically regarding their "luggage"?
I've never done this, but if you read stories by people who have, they appreciate not having 3,000 other tourists on the boat; just a few dozen or so, plus the crew members who don't talk to you.
OP here - there were zero other passengers, and it was exactly the way you say.. the crew did not talk to me.. It was great! many long hours of ocean, days, nights, out in the far blue.. with no computers at all. When I arrived in Japan I was so rested! the passage into Tokyo Bay was so memorable! it takes time.. it was an antidote and clarity..
I have read that too. It seems bizarre that it would be expensive, but there may be a supply an demand issue for the number of people who cannot or will take flight vs. the very limited number of transatlantic and transpacific ship crossings.
Think about it. A ship needs to include essentially a small apartment (with the weight of a small apartment) for a couple weeks (plus food, heat/cooling, electricity, water/sewer, upkeep for the small apartment) whereas for an airplane you just needs to do that for a chair for a few hours. A cruise ship (yes, I know, includes a bunch of luxury amenities, but still the right order of magnitude) has like 30,000 kg per passenger whereas an airplane weighs about 300 kg per passenger.
So whereas ships are more efficient per ton than airplanes, but the end result is that jet air travel is about 5-10 times as efficient per passenger-mile because it's just a chair instead of an apartment. Plus the capital utilization (renting an aluminum chair for a few hours vs a small steel apartment for a few days) aspect.
It is not their core-business like cruises or ferry companies. So there is probably very substantial overhead in coordination, billing and so on. Same goes for anything from any company, technically they can provide service and even might do, but price it is sensible due to extra work is high.
I assume it used to be far more informal and sort of a handshake deal you'd make with the captain, and then the companies formalized it but it was still cheap because no one knew/wanted to do it, but then as the possibility becomes common knowledge, there are way more people who want to do it than there are spots for, so they raise the price.
