That would be quite a planning exercise - especially trying to keep it under $30k. I guess $100/night per person is within reason...? So $36500/year per person.I’ve always been a bit of a cruise lover. I know that there are some people who live year-round on cruise ships and it’s surprisingly affordable.
You can do it for under $30,000 a year and that includes lodging and all the food you can imagine.
Something I’d definitely consider in the future for a year or two.
Do a couple of repositioning cruises a year to knock about 4 weeks off for cheap (those repo cruises are usually long and pretty inexpensive).
I think there would be times when things would get expensive in the high season. You might have to switch ports or stay a couple of nights on land. Might get tired of the same ports over and over as well...