Nothing strange about the islands apart from him raving about the stunning beaches, waterfalls, and colorful wildlife. He once found a bale of weed, he kept it and never returned to that particular island. The strange stories he has all occurred out on the ocean. Swimming in bioluminescent water. A massive shape nearly 100m long surfaced his bow in the middle of the night and paced him for hours. It turned out to be a sub.
He has many stories about the ocean, he is convinced he saw UFOs, not necessarily aliens but definitely unidentified and very unusual crafts and he saw them go into the water. I believe him, he is not the type to be into conspiracies or make things up. He embellishes his stories a little but that is just him being a good storyteller. He was in the military and navy for 40 years so he knows the ocean well. The Pacific Ocean is an enormous space, there are military outposts but due to its size, they are few and far between. The Arctic is much much more surveilled due to all the big countries wanting a piece of it and with climate change opening the Bering Strait, this becomes very valuable. Good luck with your game, may it fare well and be profitable to you.