Depending on the style guide the author or company uses, they appear either italicized or not. What about the English press AP Style?

Titles of books are italicized. If there is none, the book should be considered as being in a purely thematic category. But then, these are no books. The companies are rarely authorized to use the name of other ships and yachts. There are some owners of boats that like the name of other boats. They don’t fit the names of car makers or models like say a Subaru BRZ because of the name itself.