Struggling to write combat scenes? Don't worry! William Pringle Green's treatise, written in 1812 can help you with that. Created for sailors in particular, the treatise should be useful for shipboard scenes.
http://swordfight.uk/wp-content/uploads/2019/11/Instructions-for-training-a-ships-crew-in-the-use-of-arms-in-attack-and-defence-by-Lieutenant-William-Pringle-Green-1812.pdf