Bodies of water are frequent metaphors in poetry, perhaps due to their unfathomable depths, unknowable sprawl, and unattainable porpoises. Get a little closer to the world's wettest enigmas with today's Groupon: for $95, you get your choice of a two-hour private sailing lesson or a two-hour leisure cruise for up to three people (a $190 value) from Courageous Sailing in Charlestown.

For two hours, the sea-curious get to try their hand at sailing the Boston Harbor amid the billowing sails and ocean spume of a small boat such as the Rhodes 19—a 19-foot-long sailboat roomy enough for two students looking to grow a pair of sea legs and one skipper brave and sure who will bail you out in the event of any Kraken encounters. Nautical novices will learn how the sails work, how to steer the boat, and how to identify the wind in a leeward lineup, building a steady base upon which to stack future skills. Those with some sailing experience can simply give notice of the specific area they'd like to focus on while making their reservation. Sea explorers not interested in learning the ropy facets of sailing at all can simply lean back and enjoy a two-hour cruise while observing Boston from the water.

As a nonprofit, all proceeds from Courageous Sailing's commercial ventures go to support its children's sailing programs, which serve more than 1,000 disadvantaged children each year. The programs teach kids the fundamentals of sailing and the benefits of cooperation, and educate them about community service and environmental stewardship.