Paddling Instructor blog or TrekToday) are these Star Trek-styled wet suits for the Trekkie who has everything and can hold his breath a really long time. These are the real McCoy (pardon the pun), actual working custom made wet suits available in 3mm, 5mm or 7mm thicknesses, and also available in the gold command colour, blue science colour, or the red engineering colour. They're made by JMJ Wetsuits and available to order at roddenberry.com. No word on whether water-proof pointed-ears are available.
Memory Alpha supplied the answer. It turns out that Miles O'Brien, Chief of Operations at Deep Space Nine, liked to relax by whitewater kayaking in Quark's holosuites. He dislocated his shoulder a number of times and Quark eventually told him that the kayaking program had "gone missing" to prevent further injuries. I guess no more paddling where no one has paddled before for him.