What is the thinking behind putting thruster fin setups on big-wave guns? As I understand it the thruster works best when it can be pumped to take advantage of its extra drive. It seems that a single-fin setup would be much more efficient on a big-wave gun because it causes less drag, and you definitely don't need to gather more speed on a wave like Todos, Maverick's or Waimea. Also it seems that singles hold in much better on the long fades and drawn-out bottom turns that traditional big-wave surfing is all about. Any clues?