To get to Red Reef in OSRS, you generally travel by boat from the Great Conch area, then sail toward the quest island; one guide specifically says to start at the Great Conch, board your boat there, and sail northwest to Red Rock/Red Reef.

Fast route

  • Go to the Great Conch.
  • Board your boat there.
  • Sail to Red Reef/Red Rock as directed by the quest dialogue or marker.

During the quest

  • After arriving, you’ll need to speak with the receptionist and continue the quest steps on the island.
  • One guide notes you can unlock a Red Rock teleport for a sailor’s amulet after inspecting a sailor’s marker.

Important note

  • A guide warns not to teleport away after docking at the island, because that can cause issues with the ship and its contents.

If you want, I can also give you the exact step-by-step quest route from the start.