Mourtias Reef (North & South)

Mourtias Reef lies off the southern tip of Alonissos, with the island bulk to the north and northeast shielding it from the dominant summer Meltemi, which blows from the N-NW across the Aegean — the reason the site is so often diveable through the season. The open exposure window is the sea to the south and southeast, where the S-SSE-SE sector faces open water toward the central Aegean; a small islet about 1 km to the west and the neighbouring island of Peristera to the east and southeast trim the swell from those quarters, while the north through northwest sectors are effectively blocked by land. In practice it stays calm in typical Meltemi conditions and is knocked out mainly by southerly wind or a distant southerly swell, which build surface chop and surge over the shallow reef top.