when I introduced vectors to my students, did so with air/sea navigation which is a little down the road for your son.. a 360 degree circular protractor rather than the typical school supply half circular ones seemed to help students visualize the relationships between compass NSEW headings, and degrees of rotation 0-360 a little better ...I set up a simple land navigation lab teaching basic orienteering skills on the football field...determine length of pace... start at SW corner of goal line, 75 degrees for 22y, then 325 degrees for 45y etc..the intent was to have them identify a point of reference in the distance on the required bearing, so they would walk in a straight line...might have him make some Ranger beads to keep track of distance...5mm plastic beads and some round shoe laces work fairly well...