Prop talk, Cleavers semi cleavers and alike

[TwzteD]

Got a few questions, tried searching but haven't really found very good information.

I understand what a cleaver does and all that but what does say a semi cleaver provide that a normal cleaver does not? More bow lift? less slip? seems like drag boats tend to run semi cleavers or similar, advantages of both? To add to the mess what about a through hub vs over hub on an engine that still routes exhaust through the lower. I contacted Ron hill and his responses are very vague. I know finding the perfect prop is all trial and error but it makes it alot easier to find a starting point knowing specifically what each prop is intended to do. Then there is also 4 blade vs 3 blade.

My boat is a 13' with a pad and im running alot less hp that everyone here with a mercury 60 hp formula race (1:87 Ratio) and I have a 12x22 Merc labbed cleaver for it that I haven't ran yet as my boat is under resto and not completed yet. They run real well on many other boats like mine that run them (60-65 + mph). The merc prop is through hub because that's what UIM requires in the class, im not racing mine so im trying to find another alternative spare prop that would give similar performance but possibly better hole shot , cruising efficiency, carring a passenger etc that's why im inquiring about a semi cleaver with possibly over hub, even a 4 blade.

From what I have read a 4 blade will slow the boats top speed most of the time but will provide better carrying ability at lower speeds and better hole shot. When switching to 4 blade need to go down in size and pitch. An over hub typically is faster and allows to spin a slightly larger wheel due to the aeration on hole shot that allows the prop to slip a little more. Is this true? I haven't found any good info on semi cleavers.