Prop selection on an outboard powered work boat

[la350]

I'm a commercial salmon fisherman in Alaska. I just purchased a new boat and need help with the prop selection. The boat is an open alum skiff with a 9' beam x 24' long, shallow V hull at about 2200lbs. I just purchased a '79 Merc 150 V6 with a rebuilt power head and a clean bill of health from the local shop. This boat will be used for short trips from the beach out to my nets anchored up to a mile off shore. If the fishing has been good, I could have up to 2500lbs or so of salmon to haul back to the beach. We run the skiffs right up on the beach at speed to get 'er beached before the surf tumbles us. Aluminum props are what is commonly used and we typically go through at least one every year or so.

I'm wondering as to diameter and pitch for this application.......? Any suggestions?

Thanks,

Lance

 

[Crownie2]

Re: Prop selection on an outboard powered work boat

If you are interested in a four blade you could look at the Alpha 4, but I believe the smallest pitch available is 16" - large diameter is your friend here and it is 15".

You may well need to go lower than 16" pitch for your load and then the regular Alpha 3 blade comes in 15", 14" at 15.5" diameter and 13" at 16" diameter.

I am making strictly a guess here that 14" or 15" will be close.

Can you get some suggestions or look at other boats locally? Do you have a tach?

Good Luck

Bob

 

[la350]

Re: Prop selection on an outboard powered work boat

Bob,
Neighboring fisherman have similiar size boats but no one has a 150hp that they are running. Most are either in the 100-115 or 200hp range. I'll probably have to wait until I install the motor and then work off the tach. I was just hoping to get a decent deal on a prop or two in the off season so I was ready to go next June.

When you say 14 or 15" are you referring to pitch or diameter? The engine currently has a stainless 3 blade 14x19. I'm planning on selling it and buying a few alum props.

Thanks,

Lance

 

[Crownie2]

Re: Prop selection on an outboard powered work boat

That would be pitch.

You might be able to get an idea from the 200hp motors, although their gear ratios are higher, so is their HP so it might still be a valid starting point.

Another idea might be to try the 19" (without a load), post the results and go from there. When you add a 2,500 load you need to drop the pitch by about 3".

Also you might try to contact the boat manufacturer to see if he can offer any suggestions.

Bob