One fleet is not deployed as standard, but instead they are assumed to be hiding in wait for the other to pass by. Take one 'Contact' marker for each 250 points of ships in your fleet; assign ships or squadrons to these markers as you wish (markers can have any number of units, or none at all if desired.) Place these markers on the board as you wish, though none may be within 15cm of a board edge (they may be close to enemy ships, though.)
Once the game starts, the ambushing player may test to reveal his ships at any time; before this happens, the ships may not interact with the ships already on the board, in any way (they are assumed to be operating in low-power, heavy ECM mode; the enemy can only get a general idea of where they are.) At the beginning of their turn, the ambushing player may nominate any number of counters to try to reveal; each one rolls a Leadership test. There is a +2 Leadership modifier if the marker is 30cm from any enemy ships, a +1 modifier if the marker's group includes the fleet's Commander, and a -3 modifier if there are enemy ships within 15cm of the marker. If the test succeeds, the ships for that marker may be placed anywhere within 15cm of the marker, with any facing; if it fails, they remain hidden. In addition, if the player rolls an 11 or a 12 on the check, the ships must be place, but the _enemy_ player decides where they go and with what facing. In a group of ships with mixed Leadership, use the highest value of the ships in the group for the test.
Markers which are not revealed may move 10cm in any direction during the ambushing player's movement phase (without needing to worry about turn modes, maneuverability, or other things; they move like mines.) Radiation bursts affect the ships' Leadership as normal; Solar Flares add a +1 modifier to the _die_ _roll_ for markers checking to be revealed that turn (making it more likely that the enemy will detect them) but don't cause damage to unshielded ambushing ships.
What do you think, sirs?