After finishing the final Quest in this Chain To The Sea from lolgaroket's blog

After finishing the Lost Ark Gold final Quest in this Chain "To The Sea", gamers will receive the Island Soul, some Silver (which is usually wanted), some High Seas Coin Chests (may be changed into Pirate Coins), and subsequently the Jewel Coral. But, where's the Moss Turtle? Well, players clearly ought to take this Jewel Coral to any Luxury Merchant found in all main towns, and change it with them to pick out from one in all three different coloured Turtle Mounts.

And what's even more, there are truely two other Turtle Mounts in the game that may be obtained as well! One is the Golden Moss Turtle it's given to players on Opher Island in change for 25 Island Tokens, and the alternative is the Red Moss Turtle which calls for players to finish An Una's Task related to Buy Lost Ark Gold the "Sinking Island" Reputation Daily, for 30 Days general.