I think the horror of a storm at sea lies in the involvement of all elements, all around you. On land, at least you have solid earth beneath your feet- you can seek the quietude of shelter. In a storm at sea, the wind howls, the waves crash and fill the very air with foam, the ocean below you heaves and drops away. There is no shelter, and you will never feel as totally vulnerable or as totally alone as you do in a storm at sea. The sense that you will be swept under the surface and buried in oblivion is horrifying- your isolation means this will happen leaving even your grave unmarked and unknown. Perhaps this is what drove the crewman of the Falcon to leave the msg in the bottle: some sense of human connection, even though it would come long after his death.

I have come near this, as I stated in another thread. It is perhaps some comfort to know that the feeling of sheer terror is unsustainable for long- at some point comes acceptance and a strange surreal joy at the abandonment of hope.