I get 2 years from Propspeed but it is expensive. A cheaper and equally good option is PropOne produced by Greencorp Marine in Sydney $160 for a 250 ml kit. The reviews I have read about it are good. It used to be called Prop Gold. Picking some up next week.
Note that the $250 I quoted was for a contractor to carry out, including preparation & application. You need to remove all previous paint / propspeed and get back to a shiny prop and shaft.
I use it and have not found anything better. It does need the boat to be used regularly to prevent the growth from growing into the propspeed. Giving the prop a spin at the birth once a week is all it needs.i generally get 18 months, but with a couple of washers you get 2 years.
