It's time to drop back to first principles.
Go to your local library. Go to the children's room. Find any books they have on old-time sailing ships and 17th/18th/19th century navigation. Read them (they're often well illustrated!) Check the bibliography of each; copy down the titles. (Take notes, including the title, author, page number, and accession number of each book you take information from. You'll need this again.)
Once you have a grounding in what things looked like and what they were called, go to the adult section of the library. Find the section on historical ships and sailing (Dewey Decimal 387.204). Read all the books they have. Be sure to read the footnotes. Again, copy out the bibliographies. Take notes as before.
Now you're ready to start doing some serious research. Find books that you think you need to read (you'll have seen them mentioned, in the bibliographies if nowhere else). Interlibrary loan is your friend. Read them. Take notes. (By this time you may only need to read selected chapters.)
Okay! At the point where if you were on Jeopardy! and the final category was "old sailing ships - navigation and steering" you'd bet everything -- now you can plan your trip to one of the many historical museums that deal with the subject. Mystic Seaport, the Newport News Mariner's Museum, etc.
Go there, take notes! (Have fun, too.) Remember, all this is tax deductible!
When every new source you find quotes sources you've already read, you may be ready to write your book.
Remember: sailing ship people, like horse people and gun people are absolute sticklers for authenticity. You can't fake being an expert; you have to actually be one.
Again, have fun!