When I first started playing the game I was legit scared to go sailing because I was terrified that a sea serpent would sink my ship. Then I discovered they only spawn at night and during storms. On top of that, they are super easy to kill.
Sea Serpents really need some love. I think the whole ocean needs some love. I'd love to see sea serpents spawning during the day, introduction of 1 and 2 star serpents, actually swimming around, and maybe given a ranged attack where they spit poison or something. Just anything to make them more of a threat, because right now they are merely a source of food to be farmed.