Years ago, the stillness of Mono Lake [1] was broken by quite a bit of boat traffic. (Private boats and small tour operators still ply the salt-alkaline lake in the summer, but no major commercial water traffic remains.) The hub of this activity was the Marina a few miles north of Lee Vining.
Today, the Old Marina is merely spot off Highway 395 north of town at which you can take a short stroll down to the edge of the lake. From here you can see the two large islands in the middle of the lake, several nearby tufa towers, and much of the lakescape itself.
The boardwalk trail here is wheelchair accessible.
Links:
[1] http://www.moon.com/destinations/california/yosemite-and-the-eastern-sierra/mono-lake