Deefinitely not. Lots of people crossed the Atlantic and completed very long cruises.

To cite one who was featured in Catsailor Magazine, Roberto Pandiani sailed a Hobie 21 from Miami, US to Ilhabela, Brazil. Then he sailed another H21 from Chile to S.Paulo, via Maggelan Strait. Then he went from Cape Horn to Antartida in a highly customized H21.

Then he (finally) abandoned the H21 to participate in the Tybee - and followed to New York and Greenland. Take a look at this site (choose English).

I am sure there are more people attempting simmilar feats.

Lehitraot,