version 1/110709 by Samuel Byron
Like Mikael Segercrantz's original, this extension creates eight directions modeled on those found onboard ships: port, starboard, fore, aft, port bow, port quarter, starboard bow, and starboard quarter (the intermediate directions are unhyphenated in this adaption) and defaults to indexing the map so that the bow of the ship points north, though this can be changed by specifying "Use ship mapping direction of ___". Additionally, it adds the synonyms abaft/astern and forward/ahead for mapping aft and fore, respectively--the second in each group traditionally refers to something in front of or behind the boat.
For the player, Shipboard Directions still provides the same abbreviations for port ("p" for port; "pb", "p b", "port b", and "p bow" for port bow; "pq", "p q", "port q", and "p quarter" for port quarter), but the "sb" shortcut for starboard has been shortened even further to "s". To avoid conflicts with "south", you will need to manually tell Inform to read that as starboard, either by saying "Use shipboard directions" to change it for the entire game or by writing your own "To decide if onboard ship:" phrase (see below for an example). This will also affect which set of directions is allowed; "north" will not be allowed when the player is determined to be on a ship, for example. You can customize the error message printed when the player tries to go in an inapplicable direction by changing the "shipboard-only warning" and "compass-only warning" text variables.