You can use these maps to explore the mouths of the Irrawaddy River, which are located between its delta, and the Andaman Sea.
The maps were produced by the Japanese Imperial Army from earlier 1:63 360 (one mile to the inch) maps by the Survey of India. These WWII era maps are the latest available. Myanmar is now covered by recent 1:50 000 maps produced by the Myanmar Survey Department, but these have never been made public.
You can find several hundred of the Japanese Imperial Army / Survey of India maps of Burma in TROPICARTA’s global map archives.