On a chart, the shortest distance between 2 points is a straight line but on the world it is curved i.e. a Rhumb Line.
The game is played on a compass rose board and, as rank has its privilege, the player with the Officer stones starts by placing a yellow stone in any position on a radial.
The opponent then places a Sailor blue stone in any other position on any radial ... and so on.
Position stones on the radial lines of degrees where they intersect the concentric circles in the compass.
Place the stones, one at a time, building on those already on the board to complete &/or block new point-winning rhumb lines.