Override the rig's defenses.

Upgrade to the 5th tier hull.

Equip the Siphon Trawler.

Upgrade all 3 basic abilities.

Finish all side quests in The Pale Reach.

Catch all known species of fish in The Pale Reach.

Finish the main quest in The Pale Reach.

Equip the Icebreaker.

Obtain all other trophies.

Catch all aberrations.

Complete all side quests. One way or another.

An alternate form of combat, with an alternate path to victory. Get 20 wins in Avatar Battles. But don't obsess over the results. Let experience be your guide.