NavList:

Apart from Morrison’s excellent book, there are a few things online about the mariner’s astrolabe:

By David King (professor emeritus of the University of Frankfurt am Main and probably the person most knowlegable on astrolabes today): https://www.academia.edu/attachments/95534171/download_file?st=MTY5ODkwOTY2NSwyMTcuOTUuNjkuMTMsNjMzNzU2MQ%3D%3D&s=profile&ct=MTY5ODkwOTY2OCwxNjk4OTA5Njc2LDYzMzc1NjE=

By a group at Texas A&M University (as of 2020 containing 111 mariner's astrolabes):
https://www.academia.edu/43460654/Marine_Astrolabes_Catalogue

More books:

Stimson, Alan, The Mariner’s Astrolabe, Utrecht 1988 (a bit outdated – lists only 64 mariner’astrolabes and has some factual mistakes)

Garrido , Àlvaro, A Saga dos Astrolábios, Ilhavo 2006 (on Portuguese examples – with English text)

There has also been quite some research into the accuracy of the mariner’s astrolabe which I summed up in an article in the ‘Mariner’s Mirror’ some years ago (“On the Attempts to Assess the Accuracy of the Astrolabe. In: Mariner's Mirror, Vol. 100 (2014), Issue 2, 198 – 203) with a follow up by Nicolàs de Hilster (“Observational Methods and Procedures for the Mariner's Astrolabe”, in: Mariner's Mirror, Vol. 100 (2014), 3, 261 - 281.)

And two classics on the planispheric astrolabe for those who read French:

Michel, Henry, Traité de l’ astrolabe, Paris 1976.
D’Hollander, Raymond, L’Astrolabe – Histoire, théorie et pratique, Paris 1999.

By the way:the mariner’s astrolabe played a major role in 16th and 17th century navigation (especially Portuguese and Spanish; England, France and the Netherlands only caught up decades later). And the latitude figures arrived at in using the astrolabe are surprisingly close to modern values when comparing early latitude tables with todays figures.

Regards
Wolfgang