Not in the literal "below 32 degree" definition of freezing, but 68 degrees is cold for water temperatures. The human body can
comfortably be in any the water temperature range of 78 to 85 degrees. Anything below 70 is cold.
By the way, 68 degrees of ocean water is not the same as 68 degree air temperatures. Water has a significantly higher Heat Transfer Coefficient and absorbs the heat out of your very body quickly, thus making you feel cold. Whether or not
you perceive it to be cold is irrelevant - it's cold by it's own definition.
What? Water density nor water temperatures of the Pacific Ocean has anything to do with drowning. This is clearly getting too overwhelming for you. Step away from the keyboard and call it a day.