There are two options for the boat: you can take it as a shortcut to Hidden Falls/Inspiration Point. They also offer a one-hour tour that circles the lake.
Where we had our lunch on our hike.
Where had lunch on our hike.
Bring bear spray (yes, it's real)
Take the ferry across Jenny Lake and hike up to Inspiration Point (No. 3 on the list). The ferry costs $10 round trip or $7 one way. The ferry cuts of 2 1/2 miles of hiking.