Depth of the seabeds
A pan-like shape seabed of the Gulf of Thailand with the deepest point of about 80 meters has the main deep channel of over 50 meter deep laying on the middle of the gulf. The upper Gulf of Thailand has an inverted U-shape with the area of approximately 100 x 100 square kilometers, the deepest point of the upper Gulf of Thailand is about 40 meters on the east part while the west part is more shallower about 15 meter. The Gulf of Thailand is split from the South China Sea by two underwater ridges. The first ridge stretches south-eastward from Khota Bharu for 160 kilometers with the average depth of 50 meters. The second ridge stretches south-westward from Cape Camou for about 100 kilometers with a sill depth of about 67 meters. Moreover, there is an underwater sill that acts as a hydraulic controller of current flow in the lower Gulf of Thailand.