The least costly line I know of is Pullmantur. Their repositioning cruises across the Atlantic are frequently under $50/day for a solo passenger. US$37 / day

The least costly line I know of is Pullmantur. Their repositioning cruises across the Atlantic are frequently under $50/day for a solo passenger. US$37 / day at current exchange rates and including taxes and semi-obligatory gratuities: http://www.pullmantur.com.br/pt/cruzeiros/-/cruzeiros/posicionales/salvador-brazil/sovereign/13-noites.html http://www.pullmantur.com.br/pt/cruzeiros/-/cruzeiros/posici... US$39 / day: http://www.pullmantur.com.br/pt/cruzeiros/-/cruzeiros/transat-st-marteen-barcelona/philipsburg/horizon/12-noites.html http://www.pullmantur.com.br/pt/cruzeiros/-/cruzeiros/transa... Heads-up: English is not the primary language of most passengers, but from what I've read, the crew can accommodate it. Norwegian also has some that are under $100/day including taxes and gratuities. The one below is $968.95 for 13 days ($75/day), assuming you take the promo where the cruise line pays for the gratuities. http://www.ncl.com/cruises/STAR13DVRPDLMIATPA?itineraryCode=STAR13DVRPDLMIATPA http://www.ncl.com/cruises/STAR13DVRPDLMIATPA?itineraryCode=... (click all the way through to the final pricing page - the first page isn't what you get charged)