https://www.google.com/books/edition/Trigonometry_for_Naviga...

I found this book because I was a little rusty on my trig and most celestial navigation texts will just throw the PZX equation (and others) at you without breaking down what's actually being done with it on a mathematical level...it's just kind of treated like a magical black box without any discussion, and I'd rather have a complete understanding of what I'm doing and why. Having an application-specific approach also makes it a lot easier to learn.

I'm using it with Norie's Nautical Tables, which has the log tables and a whole lot else:

https://bluewaterweb.com/product/nories-nautical-tables-2025...

I'm sure there are plenty of free PDF's of log tables you can find though.

(I believe they used log tables on boats primarily because it's easier to use than a slide rule when everything is constantly rocking back and forth.)