 Little is known about Pulau Makin Jahat.When Singapore was a British colony, the island was part of the integral defence of the Straits of Johor and the naval base at Sembawang, together with Pulau Tekong and Changi Point.The gun battery positions on Pulau Sejahat could have been intended to protect the stretch of waters between Changi and Pulau Tekong, so as to extend the coverage provided by the neighbouring coastal defence batteries.