Descriptive signage around the lake often notes the visibility of the water used to be 100' in the days when Mark Twain explored the area, but development has reduced that figure to about 65' today. These signs are posted to reinforce the "Keep Tahoe Blue" environmental awareness campaign, but 65' of visibility in any lake is still quite remarkable—and likely something that most people have never experienced before.
As a result, the natural bays that occur around the lake appear freakishly artificial. The only comparable body of water that I can think of is the submarine lagoon at Disneyland. You get my point. But it's the reason why the lake draws so many to its inviting shores.
Coming up tomorrow: Dark skies mean bright stars.