Nick replied:
Hi thanks The question was "do they work" I had doubts that something designed to propel an optimist would propel a sprint effectively.
In the P+B catalogue, a praddle for an oppie is cheaper than one for a topper so I assume that there are different sizes. on that basis it makes things clearer.
George is right 4 knots counts as a strong old tide. One has to factor in other things like amount of beer consumed on the previous night and the number of times you have hit or missed a mark that day Three hits plus 2 knots = strong old tide today.
