My guess is that this is because land movement takes twice as long, in
general, as sea movement. You can run more sea movements in a turn than
land movements, so there's more of a chance that something will go wrong.
A simple solution might be to simply double all of the movement times.
Perhaps sea routes could go from 4 to 7 days. Land routes would be
scaled accordingly.
The other thing I could add is the Oly I feature to try various directions
in order, i.e. MOVE N E S W.
-- Rich Skrenta <skrenta@rt.com>