NavList:

I got a bit interested in this topic as a way to avoid actual work recently, and took a look at the library of congress' list of books categorized as ... well, those books in the same category with Mary Blewitt's book, VK555.

Hmm... this is pretty remarkable, there's a whole letter in the Library of Congress categorization system ("V") for "Naval Science". I'm guessing this isn't one of the more well-populated categories. "VK" is apparently "Navigation, Merchant Marine", and "VK549 - VK572" is apparently "Science of Navigation". Yikes. Here's a

https://catalog.loc.gov/vwebv/search?searchArg=VK555&searchCode=GKEY%5E*&searchType=0&recCount=25&sk=en_US

Anyhow, it turns out that there are a LOT of books in this category. Also, unfortunately, nearly all of them are newer than 1926, which I believe is the current threshold for copyright expiration in most cases (https://www.copyright.gov/help/faq/faq-duration.html). For books that were published earlier than this, I agree that archive.org is a good place to store them; there's also project gutenberg and pgdp.org which work to translate books to simple text, but for navigational texts this would probably entail the loss of all of the vital diagrams and formulae.