I was just re-reading Fatal Tide, the book by local writer David Leach on circumstances surrounding a kayaker's death in a sporting event. There's a striking moment in the book, where Leach describes a distress that is sometimes felt by Greenland kayakers when they are alone and out of sight of land. Sensory deprivation may be a factor in a sudden, awful feeling of doom. The person in the kayak may panic, flail, or wail, and it is possible that many people may have drowned at moments like this. when paddling alone. The panic and disorientation of this distress usually fades on seeing another paddler or shore, but it may return.
This upsetting event has been named kayakangst by Danish paddlers. The Inuit call this distress nangiarnaq -- to be afraid in dangerous places. It's clearly a feeling that can be related to panic attacks and anxiety disorders, or to some kinds of Meniere's syndrome and other conditions that affect the sense of balance. The closest I've come to this feeling has been over quickly: the spins and drop attacks that come from time to time since my hearing loss. Not something I'd wish on anybody!