What physics concepts can I incorporate in the rubber band powered boat that I built?

It might be interesting to see what the relationship between the number of turns wound versus the distance traveled. For example, if you wind it 10 times, 20, 30, 40 and then record the distance traveled for each. Obviously a tightly wound rubber band will spin the so rapidly, much of stored energy could be "wasted" or used less efficiently. There will be a number of turns that will result in peak efficiency, that is the most feet traveled per turn. Less energy would seem to result in fewer feet traveled but too many turns might also not translate linearly into more distance. The diameter and pitch of the prop would also be factors. A wider prop with more pitch would likely minimize efficiency losses for a tightly wound rubber band. The shape of the boat, how much water it displaces will also effect efficiency.