Are there good books focused on the naval side of the Hundred Years' War, or is it better covered in broader campaign histories?
Short answerBroader campaign histories are often the best route because the naval actions were boarding battles closely tied to the land war.
NotesBroader histories of particular phases are often the best place to find these naval actions because they were closely integrated with land campaigns. Fighting often resembled an army battle conducted across ships, with longbowmen preparing the way for boarding. Heavy armour became especially dangerous when defeated men fell into the water and drowned. This explains why the subject is dispersed across general histories and why its casualties could be severe.