HELP - Need advise on a prop 97' 40HP Merc.

[Dry Diver]

I have a 1997 40HP 2stroke Mercury SS (15") Tiller motor. It is on an Achilles 16' inflatable. I am using it for scuba diving. I am going to have three adult divers with 6 tanks and on 14 year old to be in the boat while we are down. What size prop should I be using?

Thank in advance for all the help that I know that I am going to receive.

 

[cribber]

Re: HELP - Need advise on a prop 97' 40HP Merc.

You'll need to provide a little more detail for the experts (and I'm not one by no means...) I scraped this off the Sticky posted by JB and this information will go a long way in getting you rigged up for the correct prop.

When posting a question about propellers, you cannot get a reasonable answer unless you provide the following information in your post: Items 1-4 are essential for meaningful response to most questions.
1) Performance issue you are trying to correct.
2) Current prop manufacturer, model, aluminum or stainless and as a minimum.
3) Current prop diameter and pitch (required).
4) Wide open throttle RPM and speed with an average load (very helpful)
5) Engine/drive make, model, year, and HP
6) Boat make model, year, length and weight

 

[steelespike]

Re: HELP - Need advise on a prop 97' 40HP Merc.

You may need a tach and GPS for max rpm and speed with a typical load.
A tiny tach is reasonable and easy to install.