Everybody knows the human body is mainly made of water, but not everyone realizes that water is in turn composed mostly of tiny people. Commune with your hydro-brethren with today's Groupon to Y JetSki in North Bay Village. Choose between the following options:

• For $139, you get a three-hour day or night yacht excursion (a $280 value). This Groupon covers one person; purchase one or more as gifts to bring friends or retired dolphins along for the ride.
• For $99, you get a 90-minute jet-ski rental (a $180 value). A $500, fully refundable credit-card deposit is required for the rental.

Y JetSki indulges aquatic adventurers with a fleet of luxurious boats and action-ready jet skis. Voyagers of the excursion will cruise along the shores of Miami from Star Island to the high-rises of downtown in a 60-foot Gulf Craft yacht. Tunes, complimentary drinks, and snacks make it a floating party, like a hot air balloon filled with cocktail wieners. During the nighttime outing, softer music accompanies the journey as the city lights bathe the boat in a peaceful glow. Alternatively, plot your own course with 90 minutes atop an ocean-carving jet ski. Seven days a week, the high-powered watercraft propel wave wizards along Miami's dazzling coastline and all over the ocean bay. When fatigue sets in, jetters can anchor, relax, and illicitly sand-castle-smash at the nearby sandbar.