Mesa (Bryce) with water underneath at sea level

In seed 1351816683350146382 of Minecraft 1.7 pre-release, some layered clay spikes of the Mesa (Bryce) biome occur in a Beach area with water and clay underneath them. I took two screenshots, one above and one below water level. I assume the layer of water underneath would be considered a bug, though it's sort of like a sky island, except with water instead of air.