"Industrie findet man auf der Insel so gut wie nicht."
Depends on how you use 'industry' in English. German 'Industrie' is more like an industrie plant or industrial use of the area. This sentence suggests, there are almost no indutry plants on the island (and thus, there's probably not much industry found either). Do you say: Detroit used to be full of industry, when talking about whole districts made up of industry plants? Then it would be accurate. If not, leo.org suggests industry/manufacturing/production plant for 'Industrieanlage'.
I didn't even consider that. 'so gut wie gar nicht' = a somewhat idiomatic phrase for 'kaum' (hardly, barely). 'so gut wie', when not used comparatively, is translated as practically, virtually. Some other translations, more literal to the german 'so gut wie', would be: There's practially no industry on that island. Or: Virtually no industry can be found on that island. I guess you're rather in the position to decide which translation fits best. The german 'so gut wie gar nicht' suggests that there is industry given on the island, but you really have to look very closely to find it at all and you probably wouldn't find it accidentally while enjoying your vacation there.
'as good as' would be the comparative translation. But to negate it, one would say: nicht so gut wie - not as good as.
That was my struggle. A literal translation would be "One finds industry on the island as good as not," which doesn't work in English as is. Forced to guess, I'd guess that it is a negative review of the quality of the industry (e.g., the industry makes cheap souvenirs or furniture that falls apart).
And thanks for the explanation of the idioms: "so gut wie gar nicht," versus "so gut wie," and "so gut wie" meaning "practically" or "virtually." These are so hard to figure out on my own.