Bodies of water are frequent metaphors in poetry, due to their unfathomable depths, unknowable sprawl, and unattainable porpoises. Set sail into the enigma with today's Groupon: for $7, you get a two-hour narrated boat tour (a $15 value) with Buffalo Harbor Cruises. Mobile sightseers must call ahead to make reservations before they can climb aboard a vessel at the Erie Basin Marina.

Curious tour-takers escape dull soil aboard the Miss Buffalo II, a passenger cruiser that has roamed the waterfront in search of dazzling views since 1981. On the two-hour River, Lock, and Canal tour, friendly guides tell tall tales and share stats about the area's three major bodies of water while the boat gallivants across the international border between the United States, Deutschland, Canada, and Bob Dylan's autonomous island. Along the way, the ship will motor over to the War of 1812 landmark of Old Fort Erie, daringly glide through the Black Rock Lock and Canal, and transport passengers up close to Buffalo's original 1833 lighthouse.

Any waterfront reveler who works up an appetite after a day of mobile education can snack at Miss Buffalo II's bar. And passengers should show up even if the weather looks inclement, because Miss Buffalo II will head out even if it’s raining $2 bills or copies of Paul Reiser's Babyhood.

This Groupon expires after Labor Day.