SandShips is an Icehouse game designed by Andrew Looney. It is currently unpublished.
SandShips uses 3 Treehouse sets, 3 custom-designed dice, and a special gameboard. SandShips is a strategy game for 2 to 5 players in which each player is fighting to control 3 Martian Cities at the same time.
The rules for SandShips will hopefully be released in some format soon, but I cannot say when.