Coral Cove is a landmark in Fortnite, which means it doesn’t show up on the map, and you will need to be in the area before the name will pop up in the corner of your screen. You can find Coral Cove on to the northwest of the main island, near to Sweaty Sands.
The area, being mostly out in the middle of the sea, is pretty sparse when it comes to loot, but is close enough to Sweaty Sands to make it a reasonable place to drop. You can also head from Coral Cove to nearby giant Whirlpool, and easily make your way to Pleasant Park if you need to.
The main reason people will want to find Coral Cove in Chapter 2 Season 3 is as part of the Aquaman challenges, as you need to find three Tridents there for one of the quest steps.
The Tridents can be found at Coral Cove, which you can find to the northwest of Sweaty Sands. There are three in total. One is located to the southeast of Coral Cove, the second one can be found to the northwest of Coral Cove, and the last one is located directly to the north of Coral Cove.
All three of them can be found on rocks jutting out of the sea, and are pretty easy to find. All you need to do is interact with the Trident to claim it, then move on to the next one.
The area will be quite busy, as everyone will be trying to get their skin, and you will also need to watch out for sharks, which are quite common in the area, and highly aggressive.