Kathleen's Reef is named for the wreck of the Geneva Kathleen, a three-masted schooner that sank in 1930 en route from Gulfport to Curacao. Her wooden remains have long since rotted away, but snorkelers entering from nearby Barefoot Beach can still swim to see parts of her equipment sitting in just a few feet of water. The dive site itself lies a little further out, beyond the barrier reef, and on a good day rewards divers with extensive and varied sponges, huge feather plumes, and beautiful spur and groove reef formations typical of the north side.

Look inside the roomy barrel sponges for lobsters — these surprisingly inquisitive creatures will often edge slowly from their hiding places to investigate divers with waving antennae. Yellow Tube Sponges frequently have little schools of juvenile Bluehead Wrasse teeming around them, these youngsters appearing yellow rather than blue like the adults. Just east of the mooring pin, a large overhang is a regular haunt for Spotted Drums — if spooked into a hole, stay still and they will emerge again shortly.