Complex sentence: Bligh hoped to find water and food on Tofua, then proceed to the nearby island of Tongatapu to seek help from King Poulaho (whom he knew from his visit with Cook) in provisioning the boat for a voyage to the Dutch East Indies.
Split into simpler sentences: Bligh hoped to find water and food on Tofua, then proceed to the nearby island of Tongatapu. There he intended to seek help from King Poulaho (whom he knew from his visit with Cook) in provisioning the boat for a voyage to the Dutch East Indies.