Bioluminescent Bay night kayak

Every paddle stroke lights up. The bay off Rum Point on Grand Cayman's north side holds so many glowing micro-organisms, trapped there by the slow exchange of water with the sea, that a hand dragged through it leaves a trail of light. Tours set off from the beach at Rum Point after dark in double sit-on-top kayaks, paddle along a sheltered shore into the bay, and spend about an hour and a half on the water, and on some tours a guide picks out constellations and planets overhead. There is also an electric-boat version for anyone who would rather not paddle, with a low deck that puts your hands and feet in the water.

Trips only run on the darkest nights of each month, around the new moon, because moonlight drowns the glow. You need to be comfortable in water and able to swim, and some paddling experience helps; life jackets are compulsory and there is a minimum age. Expect to get wet. Leave the bug spray and lotions on the beach (they foul the bay), and plan the ride home: taxis don't work the Rum Point area at night.