Only 2 Fleet appear in that level: one to the southeast near the gate, and the other to the northwest, obstructing direct flier traversity, as well as holding a Secret Book. They can be taken down quickly with a flier, though it is dangerous. A promoted Ross (either Pirate or Berserker) can also meet with it, though it is likely to run and/or give serious injuries to him if he is still a Pirate.
They are similar to the Transporter class, due to the fact that they have maxed Constitution.
Their 3 movement is actually only 1 movement, because moving on Sea requires 3 movement to move 1 space.