After her first two films based on her movels struggled at the box office, despite polarizing critical response, Catherine Breillat spent some time writing scripts for other filmmakers before making her directorial comeback in 1988 with 36 Fillette. One of those scripts was And the Ship Sails On (E la nave va in Italy, or Et vogue le navire in Breillat's France)... sort of. According to the IMDB, she shares both story and screenplay credit with Tonino Guerra and director Frederico Fellini; but in the actual credits initial credit goes to them and she's credited separately as "Sceneggiatore" (scriptwriter) under "Troupe Francese."
This was released in the US by Criterion in 1999. It's a pretty solid, widescreen transfer, albeit non-anamorphic and with no extras (except for a nice, little 6-page booklet).
The film was rereleased, this time for the British market, in 2006 by Infinity. In some ways their transfer is better - brighter and more vibrant; but it's misframed at 1.66:1 (as opposed to 1.85:1, thus cropping the sides of the image) and also non-anamorphic. They do, however, include a second disc with a hefty collection of extras: an hour-long documentary called Fellini: a Self Portrait (released in the US as an extra on Criterion's La Strada DVD) and two half-hour episodes of a television series on Fellini. Infinity also included 2-disc set as part of a larger boxed set, simply titled Fellini, with two of his other films, Ginger and Fred and Orchestra Rehearsal, and the rest of that Fellini TV series.
So, in the end, it's up to you. Both choices are non-anamorphic... I'd have to go with the Criterion because it's framed correctly. But the UK disc comes in at a close second, and does have a nice collection of bonus material (although none of it's really specific to this film or relates much to Breillat). You might just go with whichever is easier for you: the PAL European disc or the NTSC Criterion here in the states.
As much as double-dips generally annoy me, an updated disc from Criterion might be nice - a prettier, anamorphic transfer and some new extras (including a Breillat interview, of course!) would be pretty sweet.