Much like outer space and neglected refrigerators, the sea fascinates humankind because of its unknown depths and potentially tentacled denizens. Descend into the deep blue with today’s Groupon: for $69, you get an ocean activities package from South Pacific Watersports (a $149 total value). The package includes:

• A 15- to 20-minute bumper-tube ride (a $50 value)
• A 90-minute standup paddleboard lesson (a $99 value)<p>

South Pacific Watersports’ expert captains send patrons on thrilling aquatic excursions, promoting both watery amusement and the conservation of Hawaii’s delicate oceanic life. Adventurers cling to a rollicking bumper tube with up to three other guests as it skims the wake of Koko Marina tethered to a zooming motorboat or a benevolent plesiosaur’s neck. Up to five folks can then clamber aboard a boat to Maunalua Bay, where knowledgeable instructors lead a 20-minute course imparting the basics of standup paddleboarding before turning pupils loose on the tide. Perched atop provided boards, students draw lengthy paddles through the surf while soaking in views of the ocean floor’s inhabitants and mermaid sock hops through the bay’s crystal-clear waters. The 90-minute outing also doubles as a full-body workout as paddlers buff up arms against rippling waters and clench abs and quads to stabilize their balance.

South Pacific Watersports outfits amphibious explorers with life jackets, but requires them to bring their own swimwear, towel, sunscreen, and 20-gallon sacks for scavenged doubloons. Round-trip transportation and photography services are also available for an additional fee.

Though South Pacific Watersports sometimes features a discounted price online, this Groupon still offers the best deal available.