The poll has closed; 3 voted yes and 2 voted no on the question of whether tortoises swim.
The correct answer, Joseph's answer, is 'no.' So the "crowd" was wrong on this one (although it was essentially a tie.)
Joseph told me that tortoises do not swim, and that people find box turtles and throw them into Lake Hickory to save them and they sink like rocks and drown. Too heavy. Also, turtles have flipperlike feet and tortoises have dry, stumpier feet.
To confuse matters, some tortoises are able to swim -- but not most. Most drown.