I am Canadian Latvian dual citizen. I am sure that you aleady know of the nude beaches at Vecaki (near Riga) and Ventspils. also Palanga Lithuania (for women only) and Tallinn. Twenty years ago nudity was more common, but, I do not know why, Latvia is becoming more Americanised. Yet, in many saunas (pirts), nudity is expected. Will be back in Latvia for New Years Eve.