Here is the full list of all 10 Freediving Hunter: Spearfishing the World achievements worth 1,000 gamerscore.
You completed the training
Kill 10 fish by stoning them
Spearfish 100 fish
Shark steals 20 fish
Shoot and catch 100 fish without losing any
Reach the max player's level
Blackout 10 times
Reach the deepest point in the game
Win all the matches
Kill 50 fish by headshots