The Gulf of Ob (also known as Ob Bay) (Russian: О́бская губа́, Obskaya guba) is a bay of the Arctic Ocean, located in Northern Russia at the mouth of the Ob River.This Gulf flows into the Kara Sea between the Gydan and Yamal peninsulas. It is about 1,000 km (600 mi) long and varies in width from about 50 km (30 mi) to 80 km (50 mi), and generally runs north and south. It is relatively shallow, with an average depth from ten to twelve metres which restricts heavy sea transport.