The first time you make the Cyclops and go "woah, that's big". When you are welcomed on board. When you walk about and go "oh, engine room. And 6 power cells", when you flick all the lights on and off, when you have to start the engine, when it steers like a bus and you bonk everything I'm sight. When you first honk the horn. When you learn to drive using the cameras. When you learn you can build in it. When a creature attacks and you drop a bouy.
So many great firsts with the Cyclops.

The seatruck was fine. But it didn't seem to have the personality of the cyclops