Where to Find the Scuffed Rock in Baldur's Gate 3

Find Lae'zel: Head north of the Roadside Cliffs. You'll find two Tieflings looking at Lae'zel locked in a cage. Deal with the Tieflings (refer to the 'How to Rescue Lae'Zel' guide) and then shoot the cage to free her. You need her strength to move the rock unless you are playing a strong character yourself.

Locate the Scuffed Rock: Return to your starting area and head northwest until you reach the destroyed ship. Take the southwest exit and follow the path until you encounter Astarion. Save your game before speaking to him.

Reach the Rock: Backtrack slightly from Astarion to coordinates X: 175 Y: 267.

Move the Rock: Use the Jump ability to descend the cliff. Be cautious, as jumping straight down can cause significant damage or death without the Feather Fall skill. Walk across the water to find a small rock that stands out from its surroundings. If you are not playing a strong character, switch to Lae'zel, hover over the rock, and drag it aside to reveal a chest.