Serib Kebir, one of the best-known reefs in the El Quseir and northern Marsa Alam area, is a sprawling system of coral gardens and a labyrinth of caverns and swim-throughs. Elaborate passages with sunbeams breaking through the ceiling and some genuinely tight squeezes reward careful navigation and good buoyancy. Anemone fields, glassfish and curious reef fish fill the maze.