ship from Bergen to Quebec in 1854

I have a letter by Nils Ludvigsen Elevetun dated Madison, Wisconsin July 12, 1854. He tells his ship left Bergen May 1 and arrived in Quebec June 18. No ships listed as departing from Bergen that year fit these dates. They may of course be inaccurate. My question, however, is: are the lists complete and are the dates reliable? This emigrant was very dissatisfied with absolutely everything and he felt miserable. The census for 1865 has him back at Solvorn in Hafslo.