A bad taste joke. If one were to reiterate that death by drowning was a pleasant affair, men, alike to lemmings would possibly make the pilgrimage. Your fear of watery mass can be caused by a feint recollection of such a passing and momentary panic just prior to.
This is not surprising, as when one confronts certain spiritual realities, very strong impressions from past experience of former lives will surface, and if unredeemed and uncompleted in being worked through, shall haunt somewhat. The unpleasantness will pass however, and is no cause for alarm. Some memories beg to be put aright, and yet not all can be answered at once; and like all, must await their proper time to be reviewed and sorted through.
The confrontation of death is irksome because you are trying to come to understand split realities, and this of itself cannot be reconciled. You may be in more than one place at one time, but the consciousness may not; and the distraction of shifting consciousness is pulling as if the clothes were too tight to fit. A pig in a poke.