This is volume 5 of the Kuwata Jirou Masterpiece Selection.

(from ebookjapan):
A small, unnamed island exists in the nearby waters of South America. Its location is not clear because the island changes its position little by little due to volcanic activity. There is a cursed forest on the island, and it is said that there is a master of the forest who has been living for hundreds or thousands of years, but the master of the forest never dies thanks to the water of life that allows him to live forever. Hearing this story, the sailors search the island for the water of life... but what is waiting for them?