My stoker was not overly "directionally challenged" when we first met. I was a very avid fisherman/boater at the time and she was quick to pick up the basics of reading a navigational chart and how to hold a course by compass.

Now she has her own GPS. Its an eTrex and doesn't have all the routing capabilities of the 705 or others, but she does fine with it. Even at events where cue sheet cumulative mileage doesn't match the GPS, it's usually because of some .2-.5 mile error somewhere along the way, she picks up on the add-on or subtraction miles and does the math to tell me in advance of the next turn.

She's been telling me where to go for about 17 years now, so this comes pretty naturally to her by now.