1. Ability to determine height and terrain type manually and option to have it
reported as you cross into new ones would be swell. Better navigator would
allow more options, and give them something to do besides sit in front of a
cartography table.
2. Ability to flag rooms so crew won't enter them. Forbidding deck rooms would
create a drop in speed for the duration, forbidding lounge or galley would
create morale problems for the duration.