Here is the full list of all 29 Salt achievements.
Map 100 islands at 100% accuracy.
Obtain over 10,000 gold.
Fish up a Gigantic Mouth Seabass.
Kill the Spider Queen.
Craft The Maiden.
Obtain a legendary item.
Place a flag on a very tall mountain.
Fish up a Dragon Fish.
Hold at least 50 lore books in your inventory.
Decorate your boat with a painting.
Obtain a Hightop Bloom Flower.
Obtain a set of Turtle Armor.
Dig up some buried treasure
Craft the Pardon Pusher.
Sail past the 1000 unit mark.
Defeat the Dark Guardian
Obtain the Loreman's Lofty Axe.
Defeat Draegan on Hardcore Mode.
Obtain the Golden Compass.
Obtain the Druid Spirit Idol.
Get the Jungle Skimmy boat.
Obtain all journal inks.
Obtain the Lucky Fisherman's Hat.
Defeat every boss in the game.
Complete the main quest line.
Complete every merchant quest in the game.
Hunt and kill The Alpha Stag.
Purify the Ancient Skull.
Knock fruit from a tree and shoot it with an arrow before it hits the ground.