Hopefully someone can confirm the ship that I think it is, I spotted her from Sandown beach heading towards Portsmouth from France (Portsmouth - St. Malo I think). I'm 98% certain that it's "Bretagne" but theres a couple of other Brittany ferries ships that look similar. I think it's Bretagne because I sailed on her years ago & we came back on Quiberon which suffered an engine fire while I was on it!
(http://imageshack.us/photo/my-images/96/brittanyferry.jpg/)
My 12 megapixel Canon IXUS focused well on the company name but didn't pick up the name of the ship.