: I believe a "Cleopatra's Needle" is when the kayak floatation
: compartments fill with water and starts to go down bow or stern first.

: Please correct me if I am wrong. I am a relative newbee as well.

The most common candidates for a Cleopatra's needle are the many rec/touring boats that are sold with a bulkhead and hatch in the stern, but no floatation in the bow. When swamped, the bow sinks like a stone and the boat is left hanging vertically in the water. As you might imagine, rescuing such a cripped boat is very difficult and self-rescue is impossible.

This can also happen to a boat with bulkheads, if a hatch cover is lost or the hull is holed.