The box in question.
Now over the years we have accumulated a few sets of duo props for Naughty-Cal, three sets to be exact, but due to use and damage and multiple refurbishments they were starting to get a bit past their best. The set we took off couldn't be repaired again, they were shot. So that would leave us with just two sets and one of those is again reaching the end of it's useful lifespan. So we took the decision to bit the bullet and buy a new set of duo props for Cal. Not a cheap job by any means.
Now our original sets are all A4 propellors but Volvo Penta are phasing those out and the A and B Series props will eventually be replaced by the all new J Series props. So we decided that we may as well embrace this new technology and get a new set of J4 props.
They look very different to the older style A Series props, the blades are a different shape, size and pitch, the hub is a completely new design and they make many claims of improved efficiency, thrust and tracking. I guess we won't find out if any of this rings true until they are fitted and Naughty-Cal is back in the water and we get the chance to open her up.
The three bladed forward prop.
The four bladed rear prop