It is a pretty good system when it's right. And yes, it is surprising how much force is required when you are manually making a rudder release (from the tip). However, you really need a good bit of resistance for them to remain down and when encountering minor annoyances (like jelly fish impact at speed, etc.). During the Tybee 500, we sometimes encounter large numbers of jelly balls (relatively harmless jelly fish). We've affixed additional bunjis to help keep the rudders down because of the frequency the rudders would release in these conditions.