This is probably obvious to the hardcore players here, but it was a revelation for me. I'm in a long, long, long game on an Immense map where I'm pushing back the fully developed Dread Lords. It's turn 300 and they appeared about turn 100 at a great distance from me. Although I'm steadily pushing them back, several times they've had fleets swoop in out of the FOW and kill my fleets with transports. So I made a ship called the Super Survey that is very fast and has huge sensor range (30). I send that along with a group of fleets, and when it's time to start approaching for invasions, I just park it on guard nearby, and I can see enemy fleets approaching from great distances. This has cut my loss of transports to zero. Incidentally, I'm crushing the other AIs so badly that none have dared to attack me, although most of them are furious. But the Dread Lords present a nice challenge. I really like this game.