I plan on spending a good deal more time on land than diving on my next Indonesian trip. I found this this used book on Amazon, and it's been a fascinating introduction to Indonesian culture. Not so applicable in a diving situation, but if you want a bit more about the culture, I recommend this.
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I have a couple of books from the Culture Shock series. Some can seem kind of silly, like "Australia," but in general they are good reading. I don't have "Indonesia." I generally use them for my non-dive travels more than for dive travel, unless I'm doing something like taking a long trip that involves some off-the-beaten-path travel. For dive-only trips, I tend to stay on the well-beaten path of many divers before me, and I figure the locals have probably encountered less culturally sensitive visitors than me.
