Prop choice

[jambo]

Here's a debate for these approaching long nights.
I have two props both same pitch, one is a S/S High Five and the other is the original three bladed alumi basic prop. I have tried them both and they have different and perform well. As I cruise more than tow, which one would you favour if you were me and why?

[Bus_Boy]

What differences are we talking between the two? Speed, slip, holeshot? Without actually being able to test both props out, it's very hard to say which one i would use if for some reason i had to ditch one of them.

I would go with which ever is best suited to the conditions, or the days activities, provided of course it is practical for you to own / carry more than one propellor.

For general all round use, standard propellors offer fairly good performance. That's just my opinion though, and it has been subject to debate before.

In the end it will come down to the extra grip of the 5 blade, loss in top speed, and reduced holeshot and grip in favour of a higher top speed with the 3 blade....

If you have time, and access to many different props, then it can be worthwhile experimenting. But if it's something that you need to sink money into to find out if it works or not, then i'd avoid it...

[alfaalfa]

Hi, from your short description I would say none of them...

The High Five have tremendous grip. And lifts the stern of the boat. If you are cruising mostly in heavy sea or do a lot of water sports then this is your propeller. I use a HF with slightly low pitch for water sports and I am able to drag anything out of the water! I also change to this if a need to go out in storms. Then you always have all the power available with its grip.

But my boat does not need the stern lifting properties, and also my boat is a V-bottom with a pad and the grip or torque will easily move it from its pad with any change in speed. Really nervous handling. But with a flat bottom or heavy boat this will not be much of a problem.

Your std alu prop could be OK or rubbish. Dependent upon what alu propeller/engine you have and what properties you need out of the prop to fit the boat.
Do you need to lift the bow or stern?
If you have a lot of hydrodynamic drag then a prop can lift the boat so that you can get more speed and better handling and cruising speed. If you have enough power.

If you have a Yamaha, then they tend to have rather cleaver like alu propellers that lift the stern, but really are not able to lift the bow. On the other hand you have the elephant ears of Mercury std alu propeller then you have an allround propeller.

In my opinion, a std propeller is a one-size-fits-all kind of propeller. So you might get a better boat by changing into something that has the properties that fit your boat.

But the HF is a rather extreme propeller for hole shot with stern lift. Which suits some, but not all.

My tip would be to continue the search and find something more mainstream unless you have a strange rig...

Best of luck!

Alfa^2

[jambo]

Hi Alfa many thanks for your info appreciated. I bought my Ribcraft from a water skier with the HF already on the Mariner V6 150hp but I found I was not getting good fuel figs as you say the hole shot was brill but lost a lot at the top end and more especially if I was cruising for long spells. I do a little ringo pulling but most of all I cruise so I changed to a std alumi Mercury three blade and the results are fine, I was juust wondering if I was doing the right thing by the boat so that I maximise its power and handling.

[Pikey Dave]

Generally the more blades a prop has, the less fuel efficient it is. As always with props it's a compromise, horses for courses.