body of water, waters
我这会儿可真是驶进了陌生水域。
I really am in uncharted waters now.
“你可要小心，”他回答，“那片水域对一位年轻姑娘来说太险了。”
“You’d better be careful,” he replied. “Those waters are far too dangerous for a young lady.”
我觉得自己像是驶进了陌生水域。
I feel like I've sailed into unfamiliar waters.